Knowledge (XXG)

Born–Oppenheimer approximation

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8054:). It is easy to show that for two bodies in circular orbits around their center of mass (regardless of individual masses), the momenta of the two bodies are equal and opposite, and that for any collection of particles in the center-of-mass frame, the net momentum is zero. Given that the center-of-mass frame is the lab frame (where the molecule is stationary), the momentum of the nuclei must be equal and opposite to that of the electrons. A hand-waving justification can be derived from quantum mechanics as well. The corresponding operators do not contain mass and the molecule can be treated as a 4024: 7954:. A nice fit between the symmetry-preserved single-state treatment and the corresponding two-state treatment was obtained. This applies in particular to the reactive state-to-state probabilities (see Table III in Ref. 5a and Table III in Ref. 5b), for which the ordinary BO approximation led to erroneous results, whereas the symmetry-preserving BO approximation produced the accurate results, as they followed from solving the two coupled equations. 4741: 1471: 3162: 3700: 4448: 4437: 1188: 1960: 2560: 4019:{\displaystyle T_{\text{n}}(\mathbf {R} )_{k'k}\equiv {\big (}\mathbb {H} _{\text{n}}(\mathbf {R} ){\big )}_{k'k}=\delta _{k'k}T_{\text{n}}-\sum _{A,\alpha }{\frac {1}{M_{A}}}\langle \chi _{k'}|P_{A\alpha }|\chi _{k}\rangle _{(\mathbf {r} )}P_{A\alpha }+\langle \chi _{k'}|T_{\text{n}}|\chi _{k}\rangle _{(\mathbf {r} )}.} 2949: 81:
The approximation is widely used in quantum chemistry to speed up the computation of molecular wavefunctions and other properties for large molecules. There are cases where the assumption of separable motion no longer holds, which make the approximation lose validity (it is said to "break down"), but
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problem then consists only of the 126 electronic coordinates. This electronic computation is then repeated for other possible positions of the nuclei, i.e. deformations of the molecule. For benzene, this could be done using a grid of 36 possible nuclear position coordinates. The electronic energies
4736:{\displaystyle \langle \chi _{k'}||\chi _{k}\rangle _{(\mathbf {r} )}=iZ_{A}\sum _{i}\left\langle \chi _{k'}\left|{\frac {(\mathbf {r} _{iA})_{\alpha }}{r_{iA}^{3}}}\right|\chi _{k}\right\rangle _{(\mathbf {r} )}\quad {\text{with}}\quad \mathbf {r} _{iA}\equiv \mathbf {r} _{i}-\mathbf {R} _{A}.} 69:
in a molecule can be treated separately, based on the fact that the nuclei are much heavier than the electrons. Due to the larger relative mass of a nucleus compared to an electron, the coordinates of the nuclei in a system are approximated as fixed, while the coordinates of the electrons are
2906: 6657: 4816:, the nuclear momentum coupling term becomes large and is no longer negligible. This is the case where the BO approximation breaks down, and a coupled set of nuclear motion equations must be considered instead of the one equation appearing in the second step of the BO approximation. 7938: 8122: 736: 6118: 5925: 2770: 173: 1466:{\displaystyle H_{\text{e}}=-\sum _{i}{{\frac {1}{2}}\nabla _{i}^{2}}-\sum _{i,A}{\frac {Z_{A}}{r_{iA}}}+\sum _{i>j}{\frac {1}{r_{ij}}}+\sum _{B>A}{\frac {Z_{A}Z_{B}}{R_{AB}}}\quad {\text{and}}\quad T_{\text{n}}=-\sum _{A}{{\frac {1}{2M_{A}}}\nabla _{A}^{2}}.} 1120: 7080: 4204: 1793: 2410: 418:
mass and the masses of atomic nuclei, and correspondingly the time scales of their motion. Given the same amount of momentum, the nuclei move much more slowly than the electrons. In mathematical terms, the BO approximation consists of expressing the
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Solution of these coupled equations gives an approximation for energy and wavefunction that goes beyond the Born–Oppenheimer approximation. Unfortunately, the off-diagonal kinetic energy terms are usually difficult to handle. This is why often a
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is a molecular orbital (MO) given as a linear expansion of atomic orbitals (AOs). An AO depends visibly on the coordinates of an electron, but the nuclear coordinates are not explicit in the MO. However, upon change of geometry, i.e., change of
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Baer, Roi; Charutz, David M.; Kosloff, Ronnie; Baer, Michael (22 November 1996). "A study of conical intersection effects on scattering processes: The validity of adiabatic single-surface approximations within a quasi-Jahn–Teller model".
1014:. To that end the second step of the BO approximation is generalized to a set of coupled eigenvalue equations depending on nuclear coordinates only. Off-diagonal elements in these equations are shown to be nuclear kinetic energy terms. 3157:{\displaystyle {\big (}\mathbb {H} _{\text{e}}(\mathbf {R} ){\big )}_{k'k}\equiv \langle \chi _{k'}(\mathbf {r} ;\mathbf {R} )|H_{\text{e}}|\chi _{k}(\mathbf {r} ;\mathbf {R} )\rangle _{(\mathbf {r} )}=\delta _{k'k}E_{k}(\mathbf {R} )} 1761:
We assume that the molecule is in a homogeneous (no external force) and isotropic (no external torque) space. The only interactions are the two-body Coulomb interactions among the electrons and nuclei. The Hamiltonian is expressed in
5372: 3434: 8091:, that the same electronic state (for instance, the electronic ground state) is obtained upon small changes of the nuclear geometry. The method would give a discontinuity (jump) in the PES if electronic state switching would occur. 4894:
squared and, accordingly, is then negligible also. Only the first (diagonal) kinetic energy term in this equation survives in the case of well separated surfaces, and a diagonal, uncoupled, set of nuclear motion equations results:
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transformation is applied, which retains part of the nuclear kinetic energy terms on the diagonal, removes the kinetic energy terms from the off-diagonal and creates coupling terms between the adiabatic PESs on the off-diagonal.
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We reiterate that when two or more potential energy surfaces approach each other, or even cross, the Born–Oppenheimer approximation breaks down, and one must fall back on the coupled equations. Usually one invokes then the
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If we can neglect the off-diagonal elements the equations will uncouple and simplify drastically. In order to show when this neglect is justified, we suppress the coordinates in the notation and write, by applying the
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The relevance of the present approach was demonstrated while studying a two-arrangement-channel model (containing one inelastic channel and one reactive channel) for which the two adiabatic states were coupled by a
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consist of kinetic energies, interelectronic repulsions, internuclear repulsions, and electron–nuclear attractions, which are the terms typically included when computing the electronic structure of molecules.
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This equation is time-independent, and stationary wavefunctions for the nuclei are obtained; nevertheless, it is traditional to use the word "motion" in this context, although classically motion implies time
7733: 2781: 1688: 6909: 6914: 6841: 638: 3216: 985: 5931: 5738: 3535: 1517: 3575: 2651: 2013: 3470: 2659: 1766:, so that we do not see Planck's constant, the dielectric constant of the vacuum, electronic charge, or electronic mass in this formula. The only constants explicitly entering the formula are 1023: 7943:
In this equation the inhomogeneity ensures the symmetry for the perturbed part of the solution along any contour and therefore for the solution in the required region in configuration space.
2605: 778: 7581: 4432:{\displaystyle \langle \chi _{k'}|P_{A\alpha }|\chi _{k}\rangle _{(\mathbf {r} )}={\frac {\langle \chi _{k'}||\chi _{k}\rangle _{(\mathbf {r} )}}{E_{k}(\mathbf {R} )-E_{k'}(\mathbf {R} )}}.} 1010:
It will be discussed how the BO approximation may be derived and under which conditions it is applicable. At the same time we will show how the BO approximation may be improved by including
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Adhikari, Satrajit; Billing, Gert D. (1999). "The conical intersection effects and adiabatic single-surface approximations on scattering processes: A time-dependent wave packet approach".
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Charutz, David M.; Baer, Roi; Baer, Michael (1997). "A study of degenerate vibronic coupling effects on scattering processes: are resonances affected by degenerate vibronic coupling?".
5477: 1955:{\displaystyle T_{\text{n}}=\sum _{A}\sum _{\alpha =x,y,z}{\frac {P_{A\alpha }P_{A\alpha }}{2M_{A}}}\quad {\text{with}}\quad P_{A\alpha }=-i{\frac {\partial }{\partial R_{A\alpha }}}.} 2555:{\displaystyle P_{A\alpha }\chi _{k}(\mathbf {r} ;\mathbf {R} )=-i{\frac {\partial \chi _{k}(\mathbf {r} ;\mathbf {R} )}{\partial R_{A\alpha }}}\quad {\text{for}}\quad \alpha =x,y,z,} 462: 5444: 8066:), it follows that, indeed, the kinetic energy of the nuclei in a molecule is usually much smaller than the kinetic energy of the electrons, the mass ratio being on the order of 10. 7426: 200: 8471: 7159: 7121: 6779: 6697: 6372: 6334: 5715: 5515: 5406: 5267: 5229: 5191: 5149: 5111: 865: 329: 589:
into electronic and nuclear terms, where cross-terms between electrons and nuclei are neglected, so that the two smaller and decoupled systems can be solved more efficiently.
7589: 4892: 4849: 285: 228: 2937: 867:. Because this procedure of recomputing the electronic wave functions as a function of an infinitesimally changing nuclear geometry is reminiscent of the conditions for the 4901: 5569: 5073: 4169: 3692: 3238: 2372: 2315: 2293: 2040: 998:
is the total energy of the molecule, including contributions from electrons, nuclear vibrations, and overall rotation and translation of the molecule. In accord with the
990:
is solved. This second step of the BO approximation involves separation of vibrational, translational, and rotational motions. This can be achieved by application of the
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It will be shown that the BO approximation can be trusted whenever the PESs, obtained from the solution of the electronic Schrödinger equation, are well separated:
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the nuclear positions are no longer variable, but are constant parameters (they enter the equation "parametrically"). The electron–nucleus interactions are
227:
in the three-dimensional coordinates of the nuclei and electrons, giving 3 × 12 = 36 nuclear + 3 × 42 = 126 electronic = 162 variables for the wave function. The
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To include the correct symmetry within the Born–Oppenheimer (BO) approximation, a molecular system presented in terms of (mass-dependent) nuclear coordinates
2178:{\displaystyle H_{\text{e}}\chi _{k}(\mathbf {r} ;\mathbf {R} )=E_{k}(\mathbf {R} )\chi _{k}(\mathbf {r} ;\mathbf {R} )\quad {\text{for}}\quad k=1,\ldots ,K.} 1002:, the nuclear potential is taken to be an average over electron configurations of the sum of the electron–nuclear and internuclear electric potentials. 7085:
In order for this equation to yield a solution with the correct symmetry, it is suggested to apply a perturbation approach based on an elastic potential
5610: 3246: 7434: 7197: 4063: 8287:
Baer, Michael; Englman, Robert (1997). "A modified Born-Oppenheimer equation: application to conical intersections and other types of singularities".
406:, using it to express the mean force on the nuclei caused by the electrons and thereby skipping the calculation of the nuclear Schrödinger equation. 1522: 5732:
To study the scattering process taking place on the two lowest surfaces, one extracts from the above BO equation the two corresponding equations:
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Schrödinger equation is solved, while treating the nuclei as stationary (not "coupled" with the dynamics of the electrons). This corresponding
8271: 7968: 6652:{\displaystyle -{\frac {\hbar ^{2}}{2m}}\nabla ^{2}\chi +({\tilde {u}}_{1}-E)\chi +i{\frac {\hbar ^{2}}{2m}}\chi +i(u_{1}-u_{2})\psi _{2}=0.} 8239: 6911:. Consequently, the last term is, indeed, negligibly small at every point in the region of interest, and the equation simplifies to become 5193:
becomes a closed PES in the region of interest, with the exception of sporadic infinitesimal sites surrounding degeneracy points formed by
175:
These terms are of different orders of magnitude and the nuclear spin energy is so small that it is often omitted. The electronic energies
7933:{\displaystyle -{\frac {\hbar ^{2}}{2m}}\nabla ^{2}\eta +({\tilde {u}}_{1}-E)\eta +i{\frac {\hbar ^{2}}{2m}}\eta =(u_{1}-u_{0})\chi _{0}.} 2901:{\displaystyle \langle \chi _{k'}(\mathbf {r} ;\mathbf {R} )|\chi _{k}(\mathbf {r} ;\mathbf {R} )\rangle _{(\mathbf {r} )}=\delta _{k'k},} 231:, i.e., the computational power required to solve an eigenvalue equation, increases faster than the square of the number of coordinates. 8201: 1623: 4752: 731:{\displaystyle H_{\text{e}}(\mathbf {r} ,\mathbf {R} )\chi (\mathbf {r} ,\mathbf {R} )=E_{\text{e}}\chi (\mathbf {r} ,\mathbf {R} )} 622:
of the nuclei clamped at certain positions in space. (This first step of the BO approximation is therefore often referred to as the
6846: 6784: 6113:{\displaystyle -{\frac {\hbar ^{2}}{2m}}\nabla ^{2}\psi _{2}+({\tilde {u}}_{2}-E)\psi _{2}+{\frac {\hbar ^{2}}{2m}}\psi _{1}=0,} 5920:{\displaystyle -{\frac {\hbar ^{2}}{2m}}\nabla ^{2}\psi _{1}+({\tilde {u}}_{1}-E)\psi _{1}-{\frac {\hbar ^{2}}{2m}}\psi _{2}=0,} 247:
for the nuclei. This potential is then used for a second Schrödinger equation containing only the 36 coordinates of the nuclei.
586: 899: 8514: 3475: 1479: 2765:{\displaystyle \Psi (\mathbf {R} ,\mathbf {r} )=\sum _{k=1}^{K}\chi _{k}(\mathbf {r} ;\mathbf {R} )\phi _{k}(\mathbf {R} ),} 168:{\displaystyle E_{\text{total}}=E_{\text{electronic}}+E_{\text{vibrational}}+E_{\text{rotational}}+E_{\text{nuclear spin}}.} 3540: 3170: 5726: 2610: 1972: 1115:{\displaystyle E_{0}(\mathbf {R} )\ll E_{1}(\mathbf {R} )\ll E_{2}(\mathbf {R} )\ll \cdots {\text{ for all }}\mathbf {R} } 224: 8075:
Typically, the electronic Schrödinger equation for molecules cannot be solved exactly. Approximation methods include the
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When applying the BO approximation, two smaller, consecutive steps can be used: For a given position of the nuclei, the
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Conversely, if all surfaces are well separated, all off-diagonal terms can be neglected, and hence the whole matrix of
2571: 744: 8476: 7540: 7075:{\displaystyle -{\frac {\hbar ^{2}}{2m}}\nabla ^{2}\chi +({\tilde {u}}_{1}-E)\chi +i{\frac {\hbar ^{2}}{2m}}\chi =0.} 2404:
We will assume that the parametric dependence is continuous and differentiable, so that it is meaningful to consider
78:, the latter of whom proposed it in 1927 during a period of intense fervent in the development of quantum mechanics. 5574: 1787:
It is useful to introduce the total nuclear momentum and to rewrite the nuclear kinetic energy operator as follows:
8499: 7367:
is an arbitrary contour, and the exponential function contains the relevant symmetry as created while moving along
6702: 2374:, the LCAO coefficients obtain different values and we see corresponding changes in the functional form of the MO 7691: 6383: 1136: 5449: 57:
is the best-known mathematical approximation in molecular dynamics. Specifically, it is the assumption that the
6781:
becomes classically allowed (which happens at the vicinity of the (1, 2) degeneracy points) this implies that:
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The equation with an elastic potential can be solved, in a straightforward manner, by substitution. Thus, if
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are further discussed below. The vibronic coupling in this approach is through nuclear kinetic energy terms.
8504: 7393: 5042: 3655: 811: 630: 469: 396: 216: 7948: 250:
So, taking the most optimistic estimate for the complexity, instead of a large equation requiring at least
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on the nuclear coordinates is indicated by the symbol after the semicolon. This indicates that, although
832: 290: 7678:{\displaystyle \chi (\mathbf {q} |\Gamma )=\chi _{0}(\mathbf {q} |\Gamma )+\eta (\mathbf {q} |\Gamma ),} 604: 75: 2940: 5027:{\displaystyle \phi _{k}(\mathbf {R} )=E\phi _{k}(\mathbf {R} )\quad {\text{for}}\quad k=1,\ldots ,K,} 8426: 8383: 8340: 8296: 8164: 7963: 7951: 4865: 4822: 253: 2914: 8076: 465: 8007:
Authors often justify this step by stating that "the heavy nuclei move more slowly than the light
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is effectively zero. The third term on the right side of the expression for the matrix element of
4144: 3670: 3221: 2355: 2298: 2276: 2018: 2215:
will be taken to be real, which is possible when there are no magnetic or spin interactions. The
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The last term in this equation can be deleted for the following reasons: At those points where
6232:{\displaystyle {\tilde {u}}_{k}(\mathbf {q} )=u_{k}(\mathbf {q} )+(\hbar ^{2}/2m)\tau _{12}^{2}} 578:{\displaystyle \Psi _{\mathrm {total} }=\psi _{\mathrm {electronic} }\psi _{\mathrm {nuclear} }} 7167: 4174: 2377: 2327: 2249: 2222: 2191: 8509: 8442: 8399: 8356: 8312: 8267: 8197: 8088: 8055: 2321: 1011: 991: 868: 619: 42: 38: 17: 8481: 7370: 7350: 5528: 8434: 8391: 8348: 8304: 8259: 8172: 7973: 1731: 1701: 371: 5367:{\displaystyle -{\frac {\hbar ^{2}}{2m}}(\nabla +\tau )^{2}\Psi +(\mathbf {u} -E)\Psi =0,} 4032: 335:
being the number of grid points for the potential) and a very small calculation requiring
82:
even then the approximation is usually used as a starting point for more refined methods.
8256:
Beyond Born-Oppenheimer: Electronic Nonadiabatic Coupling Terms and Conical Intersections
3429:{\displaystyle {\boldsymbol {\phi }}(\mathbf {R} )=E{\boldsymbol {\phi }}(\mathbf {R} ).} 8430: 8387: 8344: 8300: 8168: 4746:
The matrix element of the one-electron operator appearing on the right side is finite.
1617: 593: 62: 8438: 8308: 5479:
is a diagonal matrix containing the corresponding adiabatic potential energy surfaces
2943:, is over electronic coordinates only. By definition, the matrix with general element 93:
approximation means considering molecular energy as a sum of independent terms, e.g.:
8493: 5722: 5272:
The starting point is the nuclear adiabatic BO (matrix) equation written in the form
58: 7988: 5672:{\displaystyle \mathbf {\tau } _{jk}=\langle \zeta _{j}|\nabla \zeta _{k}\rangle .} 3306:{\displaystyle H\Psi (\mathbf {R} ,\mathbf {r} )=E\Psi (\mathbf {R} ,\mathbf {r} )} 1763: 420: 220: 86: 7527:{\displaystyle -{\frac {\hbar ^{2}}{2m}}\nabla ^{2}\xi _{0}+(u_{0}-E)\xi _{0}=0.} 7337:{\displaystyle \chi _{0}(\mathbf {q} |\Gamma )=\xi _{0}(\mathbf {q} )\exp \left,} 4134:{\displaystyle \langle \chi _{k}|P_{A\alpha }|\chi _{k}\rangle _{(\mathbf {r} )}} 3577:
is diagonal, and the nuclear Hamilton matrix is non-diagonal; its off-diagonal (
8465: 8258:. Hoboken, NJ, USA: John Wiley & Sons, Inc. 28 March 2006. pp. 26–57. 368:
steps can be performed. In practice, the scaling of the problem is larger than
1609:{\displaystyle \mathbf {R} \equiv \{\mathbf {R} _{A}=(R_{Ax},R_{Ay},R_{Az})\}} 793: 239: 8446: 8403: 8360: 8316: 8177: 8152: 8234: 2320:
For example, in the molecular-orbital-linear-combination-of-atomic-orbitals
464:) of a molecule as the product of an electronic wavefunction and a nuclear ( 8263: 3643:{\displaystyle {\big (}\mathbb {H} _{\text{n}}(\mathbf {R} ){\big )}_{k'k}} 287:
hypothetical calculation steps, a series of smaller calculations requiring
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is a matrix containing the vectorial non-adiabatic coupling terms (NACT):
5151:
is considered. To ensure the validity of the BO approximation, the energy
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and formed by the two lowest BO adiabatic potential energy surfaces (PES)
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can be chosen to be always real. The off-diagonal matrix elements satisfy
27:
The notion that the motion of atomic nuclei and electrons can be separated
8230: 8012: 8008: 6291:{\displaystyle \mathbf {\tau } _{12}=\mathbf {\tau } _{12}(\mathbf {q} )} 5546: 415: 71: 66: 8018:
of electrons and nuclei is of the same order of magnitude. In that case
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and combining it with the first equation yields the (complex) equation
893:) is reintroduced, and the Schrödinger equation for the nuclear motion 882:
In the second step of the BO approximation, the nuclear kinetic energy
212: 5037:
which are the normal second step of the BO equations discussed above.
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American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer
7428:
can be shown to be a solution of the (unperturbed/elastic) equation
780:
is the electronic wavefunction for given positions of nuclei (fixed
8254:"Born-Oppenheimer Approach: Diabatization and Topological Matrix". 7583:, the full solution of the above decoupled equation takes the form 3320:
coupled eigenvalue equations depending on nuclear coordinates only
889:(containing partial derivatives with respect to the components of 402:
The slope of the potential energy surface can be used to simulate
5408:
is a column vector containing the unknown nuclear wave functions
414:
The BO approximation recognizes the large difference between the
1683:{\displaystyle r_{iA}\equiv |\mathbf {r} _{i}-\mathbf {R} _{A}|} 8461:
Resources related to the Born–Oppenheimer approximation:
4809:{\displaystyle E_{k}(\mathbf {R} )\approx E_{k'}(\mathbf {R} )} 3218:
from the left and integration over the electronic coordinates
6904:{\displaystyle u_{1}(\mathbf {q} )-u_{2}(\mathbf {q} )\sim 0} 6298:
is the (vectorial) NACT responsible for the coupling between
871:, this manner of obtaining a PES is often referred to as the 6836:{\displaystyle u_{1}(\mathbf {q} )\sim u_{2}(\mathbf {q} )} 1130:
non-relativistic, time-independent molecular Hamiltonian:
399:
to further reduce the number of variables and dimensions.
8477:
Another version of the same translation by S. M. Blinder
5049:
The Born–Oppenheimer approximation with correct symmetry
980:{\displaystyle \phi (\mathbf {R} )=E\phi (\mathbf {R} )} 8220:, 3rd ed., MIT Press, Cambridge, MA, 2009, § 28.2. 8216:
T. H. Cormen, C. E. Leiserson, R. L. Rivest, C. Stein,
8011:". Classically, this statement makes sense only if the 3530:{\displaystyle \phi _{k}(\mathbf {R} ),\ k=1,\ldots ,K} 3167:
is diagonal. After multiplication by the real function
1512:{\displaystyle \mathbf {r} \equiv \{\mathbf {r} _{i}\}} 4171:
vanish, because we assume time-reversal invariant, so
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is the solution of this equation, it is presented as
7170: 7129: 7091: 6917: 6849: 6787: 6749: 6705: 6667: 6449: 6386: 6342: 6304: 6249: 6129: 5934: 5741: 5688: 5613: 5577: 5555: 5531: 5485: 5452: 5414: 5383: 5281: 5237: 5199: 5161: 5119: 5081: 5059: 4904: 4868: 4825: 4755: 4451: 4207: 4177: 4147: 4066: 4035: 3703: 3673: 3587: 3570:{\displaystyle \mathbb {H} _{\text{e}}(\mathbf {R} )} 3543: 3478: 3445: 3329: 3249: 3224: 3211:{\displaystyle \chi _{k'}(\mathbf {r} ;\mathbf {R} )} 3173: 2952: 2917: 2784: 2662: 2613: 2574: 2413: 2380: 2358: 2330: 2301: 2279: 2252: 2225: 2194: 2051: 2021: 1975: 1796: 1734: 1704: 1626: 1525: 1482: 1191: 1139: 1026: 902: 835: 810:
in small steps and repeatedly solving the electronic
747: 641: 478: 429: 374: 341: 293: 256: 215:
molecule consists of 12 nuclei and 42 electrons. The
181: 99: 2646:{\displaystyle \chi _{k}(\mathbf {r} ;\mathbf {R} )} 2008:{\displaystyle \chi _{k}(\mathbf {r} ;\mathbf {R} )} 3465:{\displaystyle {\boldsymbol {\phi }}(\mathbf {R} )} 792:for all nuclear coordinates. The electronic energy 7932: 7719: 7677: 7575: 7526: 7420: 7379: 7359: 7336: 7183: 7153: 7115: 7074: 6903: 6835: 6773: 6735: 6691: 6651: 6424: 6366: 6328: 6290: 6231: 6112: 5919: 5709: 5671: 5596: 5563: 5537: 5509: 5471: 5438: 5400: 5366: 5261: 5223: 5185: 5155:of the system is assumed to be low enough so that 5143: 5105: 5067: 5026: 4886: 4843: 4808: 4735: 4431: 4190: 4163: 4133: 4052: 4018: 3686: 3642: 3569: 3529: 3464: 3428: 3305: 3232: 3210: 3156: 2931: 2900: 2764: 2645: 2599: 2554: 2393: 2366: 2343: 2309: 2287: 2265: 2238: 2207: 2177: 2034: 2007: 1954: 1750: 1720: 1682: 1608: 1511: 1465: 1171: 1114: 979: 859: 772: 730: 596:is neglected, that is, the corresponding operator 577: 456: 387: 360: 323: 279: 194: 167: 5549:operator with respect to the nuclear coordinates 7727:satisfies the resulting inhomogeneous equation: 4862:) can approximately be written as the matrix of 2600:{\displaystyle \Psi (\mathbf {R} ,\mathbf {r} )} 773:{\displaystyle \chi (\mathbf {r} ,\mathbf {R} )} 8196:(1st ed.). Vintage Books. pp. 65–66. 7576:{\displaystyle \chi _{0}(\mathbf {q} |\Gamma )} 6435:and the corresponding rearrangements are made: 2939:indicates that the integration, implied by the 8484:, a section from Peter Haynes' doctoral thesis 8155:[On the Quantum Theory of Molecules]. 5597:{\displaystyle \mathbf {\tau } (\mathbf {q} )} 1616:of the nuclei are with respect to a Cartesian 618:removed, i.e., the electrons still "feel" the 6736:{\displaystyle \psi _{2}(\mathbf {q} )\sim 0} 3776: 3745: 3621: 3590: 2986: 2955: 1620:. Distances between particles are written as 8: 5704: 5663: 5632: 4525: 4452: 4354: 4283: 4260: 4208: 4114: 4067: 3996: 3947: 3914: 3862: 3667:for differentiation, the matrix elements of 3095: 3008: 2857: 2785: 1603: 1534: 1506: 1491: 8146: 8144: 7720:{\displaystyle \eta (\mathbf {q} |\Gamma )} 6425:{\displaystyle \chi =\psi _{1}+i\psi _{2},} 1172:{\displaystyle H=H_{\text{e}}+T_{\text{n}}} 5472:{\displaystyle \mathbf {u} (\mathbf {q} )} 5269:(designated as (1, 2) degeneracy points). 1519:of the electrons and the position vectors 788:stands for all electronic coordinates and 607:. In the remaining electronic Hamiltonian 243:on this grid are then connected to give a 8176: 7921: 7908: 7895: 7873: 7868: 7852: 7847: 7824: 7818: 7794: 7783: 7782: 7766: 7746: 7740: 7735: 7706: 7701: 7693: 7661: 7656: 7636: 7631: 7622: 7604: 7599: 7591: 7562: 7557: 7548: 7542: 7512: 7493: 7477: 7467: 7447: 7441: 7436: 7410: 7401: 7395: 7372: 7352: 7315: 7306: 7297: 7285: 7275: 7246: 7237: 7219: 7214: 7205: 7199: 7175: 7169: 7143: 7134: 7128: 7105: 7096: 7090: 7054: 7049: 7033: 7028: 7005: 6999: 6975: 6964: 6963: 6947: 6927: 6921: 6916: 6887: 6878: 6863: 6854: 6848: 6825: 6816: 6801: 6792: 6786: 6763: 6754: 6748: 6743:by definition, and at those points where 6719: 6710: 6704: 6681: 6672: 6666: 6637: 6624: 6611: 6586: 6581: 6565: 6560: 6537: 6531: 6507: 6496: 6495: 6479: 6459: 6453: 6448: 6413: 6397: 6385: 6356: 6347: 6341: 6318: 6309: 6303: 6280: 6271: 6266: 6256: 6251: 6248: 6223: 6218: 6200: 6194: 6176: 6167: 6152: 6143: 6132: 6131: 6128: 6095: 6082: 6077: 6061: 6056: 6033: 6027: 6018: 5999: 5988: 5987: 5974: 5964: 5944: 5938: 5933: 5902: 5889: 5884: 5868: 5863: 5840: 5834: 5825: 5806: 5795: 5794: 5781: 5771: 5751: 5745: 5740: 5698: 5689: 5687: 5657: 5645: 5639: 5620: 5615: 5612: 5586: 5578: 5576: 5556: 5554: 5530: 5499: 5490: 5484: 5461: 5453: 5451: 5428: 5419: 5413: 5390: 5382: 5338: 5323: 5291: 5285: 5280: 5251: 5242: 5236: 5213: 5204: 5198: 5175: 5166: 5160: 5133: 5124: 5118: 5095: 5086: 5080: 5060: 5058: 4994: 4985: 4976: 4958: 4949: 4934: 4925: 4912: 4903: 4878: 4873: 4867: 4835: 4830: 4824: 4798: 4784: 4769: 4760: 4754: 4724: 4719: 4709: 4704: 4691: 4686: 4679: 4668: 4664: 4653: 4637: 4629: 4618: 4605: 4600: 4593: 4578: 4562: 4552: 4532: 4528: 4518: 4509: 4499: 4498: 4482: 4470: 4459: 4450: 4415: 4401: 4386: 4377: 4361: 4357: 4347: 4338: 4329: 4313: 4301: 4290: 4280: 4267: 4263: 4253: 4244: 4235: 4226: 4215: 4206: 4182: 4176: 4152: 4146: 4121: 4117: 4107: 4098: 4089: 4080: 4074: 4065: 4034: 4003: 3999: 3989: 3980: 3974: 3965: 3954: 3935: 3921: 3917: 3907: 3898: 3889: 3880: 3869: 3854: 3845: 3833: 3820: 3802: 3781: 3775: 3774: 3765: 3756: 3752: 3751: 3744: 3743: 3726: 3717: 3708: 3702: 3678: 3672: 3626: 3620: 3619: 3610: 3601: 3597: 3596: 3589: 3588: 3586: 3559: 3550: 3546: 3545: 3542: 3492: 3483: 3477: 3454: 3446: 3444: 3415: 3407: 3393: 3385: 3374: 3365: 3361: 3360: 3348: 3339: 3335: 3334: 3328: 3295: 3287: 3267: 3259: 3248: 3225: 3223: 3200: 3192: 3178: 3172: 3146: 3137: 3119: 3102: 3098: 3086: 3078: 3069: 3060: 3054: 3045: 3037: 3029: 3015: 2991: 2985: 2984: 2975: 2966: 2962: 2961: 2954: 2953: 2951: 2921: 2916: 2881: 2864: 2860: 2848: 2840: 2831: 2822: 2814: 2806: 2792: 2783: 2751: 2742: 2730: 2722: 2713: 2703: 2692: 2677: 2669: 2661: 2635: 2627: 2618: 2612: 2589: 2581: 2573: 2522: 2509: 2492: 2484: 2475: 2465: 2448: 2440: 2431: 2418: 2412: 2385: 2379: 2359: 2357: 2335: 2329: 2302: 2300: 2280: 2278: 2257: 2251: 2230: 2224: 2199: 2193: 2145: 2136: 2128: 2119: 2107: 2098: 2083: 2075: 2066: 2056: 2050: 2026: 2020: 1997: 1989: 1980: 1974: 1937: 1924: 1906: 1896: 1886: 1868: 1855: 1848: 1824: 1814: 1801: 1795: 1739: 1733: 1709: 1703: 1675: 1669: 1664: 1654: 1649: 1643: 1631: 1625: 1591: 1575: 1559: 1543: 1538: 1526: 1524: 1500: 1495: 1483: 1481: 1453: 1448: 1435: 1422: 1421: 1415: 1399: 1389: 1377: 1366: 1356: 1349: 1337: 1319: 1310: 1298: 1280: 1270: 1264: 1252: 1238: 1233: 1219: 1218: 1212: 1196: 1190: 1163: 1150: 1138: 1107: 1102: 1088: 1079: 1064: 1055: 1040: 1031: 1025: 969: 949: 932: 923: 910: 901: 849: 840: 834: 784:), is solved approximately. The quantity 762: 754: 746: 720: 712: 700: 685: 677: 663: 655: 646: 640: 550: 549: 511: 510: 484: 483: 477: 435: 434: 428: 395:, and more approximations are applied in 379: 373: 346: 340: 317: 313: 298: 292: 273: 261: 255: 186: 180: 156: 143: 130: 117: 104: 98: 8482:The Born–Oppenheimer approximation 8151:Max Born; J. Robert Oppenheimer (1927). 1780:– the atomic number and mass of nucleus 457:{\displaystyle \Psi _{\mathrm {total} }} 225:partial differential eigenvalue equation 223:and wavefunction of this molecule, is a 8113: 8056:box containing the electrons and nuclei 8000: 7821: 7743: 7444: 7002: 6924: 6534: 6456: 6191: 6030: 5941: 5837: 5748: 5439:{\displaystyle \psi _{k}(\mathbf {q} )} 5288: 4442:The matrix element in the numerator is 3447: 3408: 3386: 806:of the nuclei. Varying these positions 8192:Bird, Kai; Sherwin, Martin K. (2006). 8087:It is assumed, in accordance with the 7421:{\displaystyle \xi _{0}(\mathbf {q} )} 7969:Adiabatic process (quantum mechanics) 219:, which must be solved to obtain the 195:{\displaystyle E_{\text{electronic}}} 74:and his 23-year-old graduate student 70:dynamic. The approach is named after 7: 8243:. New York: Oxford University Press. 8240:Dynamical Theory of Crystal Lattices 8129:. Chemical Education Digital Library 8123:"The Born-Oppenheimer Approximation" 4860:Born–Oppenheimer diagonal correction 7154:{\displaystyle u_{1}(\mathbf {q} )} 7116:{\displaystyle u_{0}(\mathbf {q} )} 6774:{\displaystyle u_{2}(\mathbf {q} )} 6692:{\displaystyle u_{2}(\mathbf {q} )} 6439:Multiplying the second equation by 6377:Next a new function is introduced: 6367:{\displaystyle u_{2}(\mathbf {q} )} 6329:{\displaystyle u_{1}(\mathbf {q} )} 5710:{\displaystyle |\zeta _{n}\rangle } 5525:is the total energy of the system, 5521:is the reduced mass of the nuclei, 5510:{\displaystyle u_{k}(\mathbf {q} )} 5401:{\displaystyle \Psi (\mathbf {q} )} 5262:{\displaystyle u_{2}(\mathbf {q} )} 5224:{\displaystyle u_{1}(\mathbf {q} )} 5186:{\displaystyle u_{2}(\mathbf {q} )} 5144:{\displaystyle u_{2}(\mathbf {q} )} 5106:{\displaystyle u_{1}(\mathbf {q} )} 2565:which in general will not be zero. 1698:) and similar definitions hold for 860:{\displaystyle E_{e}(\mathbf {R} )} 585:. This enables a separation of the 324:{\displaystyle 126^{2}N=15\,876\,N} 7864: 7858: 7763: 7711: 7666: 7641: 7609: 7567: 7464: 7374: 7354: 7320: 7276: 7224: 7045: 7039: 6944: 6577: 6571: 6476: 6073: 6067: 5961: 5880: 5874: 5768: 5650: 5532: 5384: 5352: 5329: 5310: 4749:When the two surfaces come close, 4500: 3281: 3253: 2663: 2575: 2502: 2468: 1930: 1926: 1445: 1230: 569: 566: 563: 560: 557: 554: 551: 539: 536: 533: 530: 527: 524: 521: 518: 515: 512: 497: 494: 491: 488: 485: 480: 448: 445: 442: 439: 436: 431: 25: 8339:(20). AIP Publishing: 9141–9152. 8153:"Zur Quantentheorie der Molekeln" 2295:, its functional form depends on 7702: 7657: 7632: 7600: 7558: 7411: 7307: 7286: 7247: 7215: 7144: 7106: 6888: 6864: 6826: 6802: 6764: 6720: 6682: 6357: 6319: 6281: 6177: 6153: 5587: 5557: 5500: 5462: 5454: 5429: 5391: 5339: 5252: 5214: 5176: 5134: 5096: 5061: 4986: 4959: 4935: 4799: 4770: 4720: 4705: 4687: 4669: 4601: 4533: 4416: 4387: 4362: 4268: 4122: 4004: 3922: 3766: 3718: 3611: 3560: 3493: 3455: 3416: 3394: 3375: 3349: 3296: 3288: 3268: 3260: 3226: 3201: 3193: 3147: 3103: 3087: 3079: 3038: 3030: 2976: 2922: 2865: 2849: 2841: 2815: 2807: 2752: 2731: 2723: 2678: 2670: 2636: 2628: 2590: 2582: 2493: 2485: 2449: 2441: 2360: 2303: 2281: 2137: 2129: 2108: 2084: 2076: 1998: 1990: 1665: 1650: 1539: 1527: 1496: 1484: 1108: 1089: 1065: 1041: 970: 950: 933: 875:and the PES itself is called an 850: 802:depends on the chosen positions 763: 755: 721: 713: 686: 678: 664: 656: 8376:The Journal of Chemical Physics 8333:The Journal of Chemical Physics 4999: 4993: 4887:{\displaystyle P_{\alpha }^{A}} 4844:{\displaystyle P_{\alpha }^{A}} 4684: 4678: 3240:the total Schrödinger equation 2527: 2521: 2150: 2144: 1901: 1895: 1394: 1388: 592:In the first step, the nuclear 280:{\displaystyle 162^{2}=26\,244} 8058:. Since the kinetic energy is 7914: 7888: 7879: 7840: 7806: 7788: 7778: 7714: 7707: 7698: 7669: 7662: 7653: 7644: 7637: 7628: 7612: 7605: 7596: 7570: 7563: 7554: 7505: 7486: 7415: 7407: 7323: 7316: 7302: 7251: 7243: 7227: 7220: 7211: 7148: 7140: 7110: 7102: 7060: 7021: 6987: 6969: 6959: 6892: 6884: 6868: 6860: 6830: 6822: 6806: 6798: 6768: 6760: 6724: 6716: 6686: 6678: 6630: 6604: 6592: 6553: 6519: 6501: 6491: 6361: 6353: 6323: 6315: 6285: 6277: 6211: 6187: 6181: 6173: 6157: 6149: 6137: 6088: 6049: 6011: 5993: 5983: 5895: 5856: 5818: 5800: 5790: 5690: 5646: 5591: 5583: 5504: 5496: 5466: 5458: 5433: 5425: 5395: 5387: 5349: 5335: 5320: 5307: 5256: 5248: 5218: 5210: 5180: 5172: 5138: 5130: 5100: 5092: 4990: 4982: 4963: 4955: 4942: 4939: 4931: 4905: 4803: 4795: 4774: 4766: 4673: 4665: 4615: 4596: 4537: 4529: 4510: 4506: 4475: 4471: 4420: 4412: 4391: 4383: 4366: 4358: 4339: 4335: 4306: 4302: 4272: 4264: 4245: 4227: 4126: 4118: 4099: 4081: 4008: 4000: 3981: 3966: 3926: 3918: 3899: 3881: 3770: 3762: 3723: 3714: 3615: 3607: 3564: 3556: 3497: 3489: 3459: 3451: 3420: 3412: 3398: 3390: 3382: 3379: 3371: 3353: 3345: 3330: 3300: 3284: 3272: 3256: 3205: 3189: 3151: 3143: 3107: 3099: 3091: 3075: 3061: 3046: 3042: 3026: 2980: 2972: 2932:{\displaystyle (\mathbf {r} )} 2926: 2918: 2869: 2861: 2853: 2837: 2823: 2819: 2803: 2756: 2748: 2735: 2719: 2682: 2666: 2640: 2624: 2594: 2578: 2497: 2481: 2453: 2437: 2188:The electronic wave functions 2141: 2125: 2112: 2104: 2088: 2072: 2002: 1986: 1676: 1644: 1600: 1552: 1093: 1085: 1069: 1061: 1045: 1037: 974: 966: 954: 946: 940: 937: 929: 903: 854: 846: 767: 751: 725: 709: 690: 674: 668: 652: 18:Born-Oppenheimer approximation 1: 8439:10.1016/s0009-2614(96)01494-7 8309:10.1016/s0009-2614(96)01411-x 8295:(1–2). Elsevier BV: 105–108. 2273:is a real-valued function of 603:is subtracted from the total 8472:Translation by S. M. Blinder 8382:(1). AIP Publishing: 40–47. 5564:{\displaystyle \mathbf {q} } 5068:{\displaystyle \mathbf {q} } 4164:{\displaystyle P_{A\alpha }} 3687:{\displaystyle T_{\text{n}}} 3233:{\displaystyle \mathbf {r} } 2367:{\displaystyle \mathbf {R} } 2310:{\displaystyle \mathbf {R} } 2288:{\displaystyle \mathbf {r} } 2035:{\displaystyle H_{\text{e}}} 30:Not to be confused with the 8425:(6). Elsevier BV: 629–637. 5721:assumed to form a complete 1690:(distance between electron 361:{\displaystyle 36^{2}=1296} 8531: 8218:Introduction to Algorithms 7161:at the asymptotic region. 5717:are eigenfunctions of the 2042:, that is, we have solved 1969:electronic eigenfunctions 29: 7184:{\displaystyle \chi _{0}} 4191:{\displaystyle \chi _{k}} 2394:{\displaystyle \chi _{k}} 2344:{\displaystyle \chi _{k}} 2266:{\displaystyle \chi _{k}} 2239:{\displaystyle \chi _{k}} 2208:{\displaystyle \chi _{k}} 8419:Chemical Physics Letters 8289:Chemical Physics Letters 8178:10.1002/andp.19273892002 7979:Born–Huang approximation 3316:is turned into a set of 2911:and where the subscript 2607:is expanded in terms of 2568:The total wave function 1000:Hellmann–Feynman theorem 827:potential energy surface 245:potential energy surface 229:computational complexity 7984:Franck–Condon principle 7380:{\displaystyle \Gamma } 7360:{\displaystyle \Gamma } 7123:, which coincides with 6699:is classically closed, 5725:in the given region in 5538:{\displaystyle \nabla } 873:adiabatic approximation 397:computational chemistry 8264:10.1002/0471780081.ch2 7934: 7721: 7679: 7577: 7528: 7422: 7381: 7361: 7338: 7185: 7155: 7117: 7076: 6905: 6837: 6775: 6737: 6693: 6653: 6426: 6368: 6330: 6292: 6233: 6114: 5921: 5719:electronic Hamiltonian 5711: 5673: 5598: 5565: 5539: 5511: 5473: 5440: 5402: 5368: 5263: 5225: 5187: 5145: 5107: 5069: 5028: 4888: 4845: 4810: 4737: 4433: 4192: 4165: 4135: 4054: 4020: 3688: 3644: 3571: 3531: 3466: 3430: 3307: 3234: 3212: 3158: 2933: 2902: 2766: 2708: 2647: 2601: 2556: 2395: 2368: 2345: 2311: 2289: 2267: 2240: 2209: 2179: 2036: 2009: 1956: 1752: 1751:{\displaystyle R_{AB}} 1722: 1721:{\displaystyle r_{ij}} 1684: 1610: 1513: 1467: 1173: 1116: 981: 861: 774: 732: 579: 458: 389: 362: 325: 281: 196: 169: 47:Born–Oppenheimer 8515:J. Robert Oppenheimer 7935: 7722: 7680: 7578: 7529: 7423: 7382: 7362: 7339: 7186: 7156: 7118: 7077: 6906: 6838: 6776: 6738: 6694: 6654: 6427: 6369: 6331: 6293: 6234: 6115: 5922: 5712: 5674: 5599: 5566: 5540: 5512: 5474: 5441: 5403: 5369: 5264: 5226: 5188: 5146: 5108: 5070: 5029: 4889: 4846: 4811: 4738: 4434: 4193: 4166: 4136: 4055: 4021: 3689: 3645: 3572: 3532: 3467: 3431: 3308: 3235: 3213: 3159: 2934: 2903: 2767: 2688: 2648: 2602: 2557: 2396: 2369: 2346: 2312: 2290: 2268: 2241: 2217:parametric dependence 2210: 2180: 2037: 2010: 1957: 1753: 1723: 1685: 1611: 1514: 1476:The position vectors 1468: 1174: 1117: 982: 862: 775: 733: 605:molecular Hamiltonian 580: 459: 390: 388:{\displaystyle n^{2}} 363: 326: 282: 197: 170: 76:J. Robert Oppenheimer 8466:The original article 8127:Chemistry Libretexts 7964:Adiabatic ionization 7952:conical intersection 7734: 7692: 7590: 7541: 7435: 7394: 7371: 7351: 7198: 7168: 7127: 7089: 6915: 6847: 6785: 6747: 6703: 6665: 6447: 6384: 6340: 6302: 6247: 6127: 5932: 5739: 5686: 5611: 5575: 5553: 5529: 5483: 5450: 5412: 5381: 5279: 5235: 5197: 5159: 5117: 5079: 5057: 4902: 4866: 4823: 4753: 4449: 4205: 4175: 4145: 4064: 4053:{\displaystyle k'=k} 4033: 3701: 3671: 3585: 3541: 3476: 3443: 3327: 3247: 3222: 3171: 2950: 2915: 2782: 2660: 2611: 2572: 2411: 2378: 2356: 2328: 2299: 2277: 2250: 2223: 2192: 2049: 2019: 1973: 1794: 1732: 1702: 1624: 1523: 1480: 1189: 1137: 1024: 900: 833: 812:Schrödinger equation 745: 639: 631:Schrödinger equation 587:Hamiltonian operator 476: 427: 410:Detailed description 372: 339: 291: 254: 217:Schrödinger equation 179: 97: 8431:1997CPL...265..629C 8388:1999JChPh.111...40A 8345:1996JChPh.105.9141B 8301:1997CPL...265..105B 8169:1927AnP...389..457B 8077:Hartree-Fock method 6228: 5727:configuration space 4883: 4840: 4642: 1458: 1243: 1104: for all  8157:Annalen der Physik 7930: 7717: 7675: 7573: 7524: 7418: 7377: 7357: 7334: 7181: 7151: 7113: 7072: 6901: 6833: 6771: 6733: 6689: 6649: 6422: 6364: 6326: 6288: 6229: 6214: 6110: 5917: 5707: 5669: 5594: 5561: 5535: 5507: 5469: 5436: 5398: 5364: 5259: 5221: 5183: 5141: 5103: 5065: 5024: 4884: 4869: 4841: 4826: 4806: 4733: 4625: 4567: 4429: 4188: 4161: 4131: 4060:) matrix elements 4050: 4016: 3844: 3684: 3640: 3567: 3527: 3462: 3439:The column vector 3426: 3303: 3230: 3208: 3154: 2929: 2898: 2762: 2643: 2597: 2552: 2391: 2364: 2341: 2307: 2285: 2263: 2236: 2205: 2175: 2032: 2005: 1952: 1847: 1819: 1748: 1718: 1680: 1606: 1509: 1463: 1444: 1420: 1348: 1309: 1263: 1229: 1217: 1169: 1126:We start from the 1112: 977: 857: 770: 728: 575: 454: 404:molecular dynamics 385: 358: 321: 277: 192: 165: 32:Born approximation 8500:Quantum chemistry 8273:978-0-471-78008-3 8089:adiabatic theorem 7838: 7791: 7760: 7461: 7019: 6972: 6941: 6551: 6504: 6473: 6140: 6047: 5996: 5958: 5854: 5803: 5765: 5305: 4997: 4915: 4682: 4643: 4558: 4424: 4332: 3977: 3860: 3829: 3823: 3759: 3711: 3681: 3604: 3579:vibronic coupling 3553: 3505: 3368: 3342: 3057: 2969: 2525: 2519: 2219:of the functions 2148: 2059: 2029: 1947: 1899: 1893: 1820: 1810: 1804: 1442: 1411: 1402: 1392: 1386: 1333: 1328: 1294: 1289: 1248: 1227: 1208: 1199: 1166: 1153: 1105: 1012:vibronic coupling 994:. The eigenvalue 992:Eckart conditions 926: 913: 877:adiabatic surface 869:adiabatic theorem 821:as a function of 703: 649: 620:Coulomb potential 189: 159: 146: 133: 120: 107: 43:molecular physics 39:quantum chemistry 16:(Redirected from 8522: 8451: 8450: 8414: 8408: 8407: 8396:10.1063/1.479360 8371: 8365: 8364: 8353:10.1063/1.472748 8327: 8321: 8320: 8284: 8278: 8277: 8251: 8245: 8244: 8227: 8221: 8214: 8208: 8207: 8189: 8183: 8182: 8180: 8148: 8139: 8138: 8136: 8134: 8118: 8102: 8098: 8092: 8085: 8079: 8073: 8067: 8005: 7974:Avoided crossing 7939: 7937: 7936: 7931: 7926: 7925: 7913: 7912: 7900: 7899: 7878: 7877: 7872: 7857: 7856: 7851: 7839: 7837: 7829: 7828: 7819: 7799: 7798: 7793: 7792: 7784: 7771: 7770: 7761: 7759: 7751: 7750: 7741: 7726: 7724: 7723: 7718: 7710: 7705: 7684: 7682: 7681: 7676: 7665: 7660: 7640: 7635: 7627: 7626: 7608: 7603: 7582: 7580: 7579: 7574: 7566: 7561: 7553: 7552: 7533: 7531: 7530: 7525: 7517: 7516: 7498: 7497: 7482: 7481: 7472: 7471: 7462: 7460: 7452: 7451: 7442: 7427: 7425: 7424: 7419: 7414: 7406: 7405: 7386: 7384: 7383: 7378: 7366: 7364: 7363: 7358: 7343: 7341: 7340: 7335: 7330: 7326: 7319: 7314: 7310: 7301: 7293: 7289: 7280: 7279: 7250: 7242: 7241: 7223: 7218: 7210: 7209: 7190: 7188: 7187: 7182: 7180: 7179: 7160: 7158: 7157: 7152: 7147: 7139: 7138: 7122: 7120: 7119: 7114: 7109: 7101: 7100: 7081: 7079: 7078: 7073: 7059: 7058: 7053: 7038: 7037: 7032: 7020: 7018: 7010: 7009: 7000: 6980: 6979: 6974: 6973: 6965: 6952: 6951: 6942: 6940: 6932: 6931: 6922: 6910: 6908: 6907: 6902: 6891: 6883: 6882: 6867: 6859: 6858: 6842: 6840: 6839: 6834: 6829: 6821: 6820: 6805: 6797: 6796: 6780: 6778: 6777: 6772: 6767: 6759: 6758: 6742: 6740: 6739: 6734: 6723: 6715: 6714: 6698: 6696: 6695: 6690: 6685: 6677: 6676: 6658: 6656: 6655: 6650: 6642: 6641: 6629: 6628: 6616: 6615: 6591: 6590: 6585: 6570: 6569: 6564: 6552: 6550: 6542: 6541: 6532: 6512: 6511: 6506: 6505: 6497: 6484: 6483: 6474: 6472: 6464: 6463: 6454: 6431: 6429: 6428: 6423: 6418: 6417: 6402: 6401: 6373: 6371: 6370: 6365: 6360: 6352: 6351: 6335: 6333: 6332: 6327: 6322: 6314: 6313: 6297: 6295: 6294: 6289: 6284: 6276: 6275: 6270: 6261: 6260: 6255: 6238: 6236: 6235: 6230: 6227: 6222: 6204: 6199: 6198: 6180: 6172: 6171: 6156: 6148: 6147: 6142: 6141: 6133: 6119: 6117: 6116: 6111: 6100: 6099: 6087: 6086: 6081: 6066: 6065: 6060: 6048: 6046: 6038: 6037: 6028: 6023: 6022: 6004: 6003: 5998: 5997: 5989: 5979: 5978: 5969: 5968: 5959: 5957: 5949: 5948: 5939: 5926: 5924: 5923: 5918: 5907: 5906: 5894: 5893: 5888: 5873: 5872: 5867: 5855: 5853: 5845: 5844: 5835: 5830: 5829: 5811: 5810: 5805: 5804: 5796: 5786: 5785: 5776: 5775: 5766: 5764: 5756: 5755: 5746: 5716: 5714: 5713: 5708: 5703: 5702: 5693: 5678: 5676: 5675: 5670: 5662: 5661: 5649: 5644: 5643: 5628: 5627: 5619: 5603: 5601: 5600: 5595: 5590: 5582: 5570: 5568: 5567: 5562: 5560: 5544: 5542: 5541: 5536: 5516: 5514: 5513: 5508: 5503: 5495: 5494: 5478: 5476: 5475: 5470: 5465: 5457: 5445: 5443: 5442: 5437: 5432: 5424: 5423: 5407: 5405: 5404: 5399: 5394: 5373: 5371: 5370: 5365: 5342: 5328: 5327: 5306: 5304: 5296: 5295: 5286: 5268: 5266: 5265: 5260: 5255: 5247: 5246: 5230: 5228: 5227: 5222: 5217: 5209: 5208: 5192: 5190: 5189: 5184: 5179: 5171: 5170: 5150: 5148: 5147: 5142: 5137: 5129: 5128: 5112: 5110: 5109: 5104: 5099: 5091: 5090: 5074: 5072: 5071: 5066: 5064: 5033: 5031: 5030: 5025: 4998: 4995: 4989: 4981: 4980: 4962: 4954: 4953: 4938: 4930: 4929: 4917: 4916: 4913: 4893: 4891: 4890: 4885: 4882: 4877: 4850: 4848: 4847: 4842: 4839: 4834: 4815: 4813: 4812: 4807: 4802: 4794: 4793: 4792: 4773: 4765: 4764: 4742: 4740: 4739: 4734: 4729: 4728: 4723: 4714: 4713: 4708: 4699: 4698: 4690: 4683: 4680: 4677: 4676: 4672: 4663: 4659: 4658: 4657: 4648: 4644: 4641: 4636: 4624: 4623: 4622: 4613: 4612: 4604: 4594: 4588: 4587: 4586: 4566: 4557: 4556: 4541: 4540: 4536: 4523: 4522: 4513: 4505: 4504: 4503: 4490: 4489: 4474: 4469: 4468: 4467: 4438: 4436: 4435: 4430: 4425: 4423: 4419: 4411: 4410: 4409: 4390: 4382: 4381: 4371: 4370: 4369: 4365: 4352: 4351: 4342: 4334: 4333: 4330: 4321: 4320: 4305: 4300: 4299: 4298: 4281: 4276: 4275: 4271: 4258: 4257: 4248: 4243: 4242: 4230: 4225: 4224: 4223: 4197: 4195: 4194: 4189: 4187: 4186: 4170: 4168: 4167: 4162: 4160: 4159: 4141:of the operator 4140: 4138: 4137: 4132: 4130: 4129: 4125: 4112: 4111: 4102: 4097: 4096: 4084: 4079: 4078: 4059: 4057: 4056: 4051: 4043: 4025: 4023: 4022: 4017: 4012: 4011: 4007: 3994: 3993: 3984: 3979: 3978: 3975: 3969: 3964: 3963: 3962: 3943: 3942: 3930: 3929: 3925: 3912: 3911: 3902: 3897: 3896: 3884: 3879: 3878: 3877: 3861: 3859: 3858: 3846: 3843: 3825: 3824: 3821: 3815: 3814: 3810: 3794: 3793: 3789: 3780: 3779: 3769: 3761: 3760: 3757: 3755: 3749: 3748: 3739: 3738: 3734: 3721: 3713: 3712: 3709: 3693: 3691: 3690: 3685: 3683: 3682: 3679: 3649: 3647: 3646: 3641: 3639: 3638: 3634: 3625: 3624: 3614: 3606: 3605: 3602: 3600: 3594: 3593: 3576: 3574: 3573: 3568: 3563: 3555: 3554: 3551: 3549: 3536: 3534: 3533: 3528: 3503: 3496: 3488: 3487: 3471: 3469: 3468: 3463: 3458: 3450: 3435: 3433: 3432: 3427: 3419: 3411: 3397: 3389: 3378: 3370: 3369: 3366: 3364: 3352: 3344: 3343: 3340: 3338: 3312: 3310: 3309: 3304: 3299: 3291: 3271: 3263: 3239: 3237: 3236: 3231: 3229: 3217: 3215: 3214: 3209: 3204: 3196: 3188: 3187: 3186: 3163: 3161: 3160: 3155: 3150: 3142: 3141: 3132: 3131: 3127: 3111: 3110: 3106: 3090: 3082: 3074: 3073: 3064: 3059: 3058: 3055: 3049: 3041: 3033: 3025: 3024: 3023: 3004: 3003: 2999: 2990: 2989: 2979: 2971: 2970: 2967: 2965: 2959: 2958: 2941:bra–ket notation 2938: 2936: 2935: 2930: 2925: 2907: 2905: 2904: 2899: 2894: 2893: 2889: 2873: 2872: 2868: 2852: 2844: 2836: 2835: 2826: 2818: 2810: 2802: 2801: 2800: 2771: 2769: 2768: 2763: 2755: 2747: 2746: 2734: 2726: 2718: 2717: 2707: 2702: 2681: 2673: 2652: 2650: 2649: 2644: 2639: 2631: 2623: 2622: 2606: 2604: 2603: 2598: 2593: 2585: 2561: 2559: 2558: 2553: 2526: 2523: 2520: 2518: 2517: 2516: 2500: 2496: 2488: 2480: 2479: 2466: 2452: 2444: 2436: 2435: 2426: 2425: 2400: 2398: 2397: 2392: 2390: 2389: 2373: 2371: 2370: 2365: 2363: 2350: 2348: 2347: 2342: 2340: 2339: 2316: 2314: 2313: 2308: 2306: 2294: 2292: 2291: 2286: 2284: 2272: 2270: 2269: 2264: 2262: 2261: 2245: 2243: 2242: 2237: 2235: 2234: 2214: 2212: 2211: 2206: 2204: 2203: 2184: 2182: 2181: 2176: 2149: 2146: 2140: 2132: 2124: 2123: 2111: 2103: 2102: 2087: 2079: 2071: 2070: 2061: 2060: 2057: 2041: 2039: 2038: 2033: 2031: 2030: 2027: 2014: 2012: 2011: 2006: 2001: 1993: 1985: 1984: 1965:Suppose we have 1961: 1959: 1958: 1953: 1948: 1946: 1945: 1944: 1925: 1914: 1913: 1900: 1897: 1894: 1892: 1891: 1890: 1877: 1876: 1875: 1863: 1862: 1849: 1846: 1818: 1806: 1805: 1802: 1757: 1755: 1754: 1749: 1747: 1746: 1727: 1725: 1724: 1719: 1717: 1716: 1689: 1687: 1686: 1681: 1679: 1674: 1673: 1668: 1659: 1658: 1653: 1647: 1639: 1638: 1615: 1613: 1612: 1607: 1599: 1598: 1583: 1582: 1567: 1566: 1548: 1547: 1542: 1530: 1518: 1516: 1515: 1510: 1505: 1504: 1499: 1487: 1472: 1470: 1469: 1464: 1459: 1457: 1452: 1443: 1441: 1440: 1439: 1423: 1419: 1404: 1403: 1400: 1393: 1390: 1387: 1385: 1384: 1372: 1371: 1370: 1361: 1360: 1350: 1347: 1329: 1327: 1326: 1311: 1308: 1290: 1288: 1287: 1275: 1274: 1265: 1262: 1244: 1242: 1237: 1228: 1220: 1216: 1201: 1200: 1197: 1178: 1176: 1175: 1170: 1168: 1167: 1164: 1155: 1154: 1151: 1121: 1119: 1118: 1113: 1111: 1106: 1103: 1092: 1084: 1083: 1068: 1060: 1059: 1044: 1036: 1035: 986: 984: 983: 978: 973: 953: 936: 928: 927: 924: 915: 914: 911: 866: 864: 863: 858: 853: 845: 844: 779: 777: 776: 771: 766: 758: 737: 735: 734: 729: 724: 716: 705: 704: 701: 689: 681: 667: 659: 651: 650: 647: 626:approximation.) 584: 582: 581: 576: 574: 573: 572: 544: 543: 542: 502: 501: 500: 472:) wavefunction. 463: 461: 460: 455: 453: 452: 451: 394: 392: 391: 386: 384: 383: 367: 365: 364: 359: 351: 350: 330: 328: 327: 322: 303: 302: 286: 284: 283: 278: 266: 265: 201: 199: 198: 193: 191: 190: 187: 174: 172: 171: 166: 161: 160: 157: 148: 147: 144: 135: 134: 131: 122: 121: 118: 109: 108: 105: 21: 8530: 8529: 8525: 8524: 8523: 8521: 8520: 8519: 8490: 8489: 8459: 8454: 8416: 8415: 8411: 8373: 8372: 8368: 8329: 8328: 8324: 8286: 8285: 8281: 8274: 8253: 8252: 8248: 8229: 8228: 8224: 8215: 8211: 8204: 8191: 8190: 8186: 8163:(20): 457–484. 8150: 8149: 8142: 8132: 8130: 8121:Hanson, David. 8120: 8119: 8115: 8111: 8106: 8105: 8099: 8095: 8086: 8082: 8074: 8070: 8053: 8042: 8031: 8024: 8006: 8002: 7997: 7960: 7917: 7904: 7891: 7867: 7846: 7830: 7820: 7781: 7762: 7752: 7742: 7732: 7731: 7690: 7689: 7618: 7588: 7587: 7544: 7539: 7538: 7508: 7489: 7473: 7463: 7453: 7443: 7433: 7432: 7397: 7392: 7391: 7369: 7368: 7349: 7348: 7305: 7284: 7271: 7264: 7260: 7233: 7201: 7196: 7195: 7171: 7166: 7165: 7130: 7125: 7124: 7092: 7087: 7086: 7048: 7027: 7011: 7001: 6962: 6943: 6933: 6923: 6913: 6912: 6874: 6850: 6845: 6844: 6812: 6788: 6783: 6782: 6750: 6745: 6744: 6706: 6701: 6700: 6668: 6663: 6662: 6633: 6620: 6607: 6580: 6559: 6543: 6533: 6494: 6475: 6465: 6455: 6445: 6444: 6409: 6393: 6382: 6381: 6343: 6338: 6337: 6305: 6300: 6299: 6265: 6250: 6245: 6244: 6190: 6163: 6130: 6125: 6124: 6091: 6076: 6055: 6039: 6029: 6014: 5986: 5970: 5960: 5950: 5940: 5930: 5929: 5898: 5883: 5862: 5846: 5836: 5821: 5793: 5777: 5767: 5757: 5747: 5737: 5736: 5694: 5684: 5683: 5653: 5635: 5614: 5609: 5608: 5573: 5572: 5551: 5550: 5527: 5526: 5486: 5481: 5480: 5448: 5447: 5415: 5410: 5409: 5379: 5378: 5319: 5297: 5287: 5277: 5276: 5238: 5233: 5232: 5200: 5195: 5194: 5162: 5157: 5156: 5120: 5115: 5114: 5082: 5077: 5076: 5055: 5054: 5051: 5045:approximation. 4972: 4945: 4921: 4908: 4900: 4899: 4864: 4863: 4857: 4821: 4820: 4785: 4780: 4756: 4751: 4750: 4718: 4703: 4685: 4649: 4614: 4599: 4595: 4589: 4579: 4574: 4573: 4569: 4568: 4548: 4524: 4514: 4494: 4478: 4460: 4455: 4447: 4446: 4402: 4397: 4373: 4372: 4353: 4343: 4325: 4309: 4291: 4286: 4282: 4259: 4249: 4231: 4216: 4211: 4203: 4202: 4178: 4173: 4172: 4148: 4143: 4142: 4113: 4103: 4085: 4070: 4062: 4061: 4036: 4031: 4030: 3995: 3985: 3970: 3955: 3950: 3931: 3913: 3903: 3885: 3870: 3865: 3850: 3816: 3803: 3798: 3782: 3773: 3750: 3727: 3722: 3704: 3699: 3698: 3674: 3669: 3668: 3627: 3618: 3595: 3583: 3582: 3544: 3539: 3538: 3479: 3474: 3473: 3441: 3440: 3359: 3333: 3325: 3324: 3245: 3244: 3220: 3219: 3179: 3174: 3169: 3168: 3133: 3120: 3115: 3094: 3065: 3050: 3016: 3011: 2992: 2983: 2960: 2948: 2947: 2913: 2912: 2882: 2877: 2856: 2827: 2793: 2788: 2780: 2779: 2738: 2709: 2658: 2657: 2614: 2609: 2608: 2570: 2569: 2505: 2501: 2471: 2467: 2427: 2414: 2409: 2408: 2381: 2376: 2375: 2354: 2353: 2331: 2326: 2325: 2324:approximation, 2297: 2296: 2275: 2274: 2253: 2248: 2247: 2226: 2221: 2220: 2195: 2190: 2189: 2115: 2094: 2062: 2052: 2047: 2046: 2022: 2017: 2016: 1976: 1971: 1970: 1933: 1929: 1902: 1882: 1878: 1864: 1851: 1850: 1797: 1792: 1791: 1778: 1771: 1735: 1730: 1729: 1705: 1700: 1699: 1663: 1648: 1627: 1622: 1621: 1587: 1571: 1555: 1537: 1521: 1520: 1494: 1478: 1477: 1431: 1427: 1395: 1373: 1362: 1352: 1351: 1315: 1276: 1266: 1192: 1187: 1186: 1159: 1146: 1135: 1134: 1075: 1051: 1027: 1022: 1021: 1008: 919: 906: 898: 897: 888: 836: 831: 830: 820: 801: 743: 742: 696: 642: 637: 636: 629:The electronic 613: 602: 545: 506: 479: 474: 473: 430: 425: 424: 412: 375: 370: 369: 342: 337: 336: 294: 289: 288: 257: 252: 251: 209: 182: 177: 176: 152: 139: 126: 113: 100: 95: 94: 35: 28: 23: 22: 15: 12: 11: 5: 8528: 8526: 8518: 8517: 8512: 8507: 8505:Approximations 8502: 8492: 8491: 8486: 8485: 8479: 8474: 8469: 8458: 8457:External links 8455: 8453: 8452: 8409: 8366: 8322: 8279: 8272: 8246: 8237:(1954). "IV". 8222: 8209: 8203:978-0375726262 8202: 8184: 8140: 8112: 8110: 8107: 8104: 8103: 8093: 8080: 8068: 8051: 8040: 8029: 8022: 7999: 7998: 7996: 7993: 7992: 7991: 7986: 7981: 7976: 7971: 7966: 7959: 7956: 7941: 7940: 7929: 7924: 7920: 7916: 7911: 7907: 7903: 7898: 7894: 7890: 7887: 7884: 7881: 7876: 7871: 7866: 7863: 7860: 7855: 7850: 7845: 7842: 7836: 7833: 7827: 7823: 7817: 7814: 7811: 7808: 7805: 7802: 7797: 7790: 7787: 7780: 7777: 7774: 7769: 7765: 7758: 7755: 7749: 7745: 7739: 7716: 7713: 7709: 7704: 7700: 7697: 7686: 7685: 7674: 7671: 7668: 7664: 7659: 7655: 7652: 7649: 7646: 7643: 7639: 7634: 7630: 7625: 7621: 7617: 7614: 7611: 7607: 7602: 7598: 7595: 7572: 7569: 7565: 7560: 7556: 7551: 7547: 7535: 7534: 7523: 7520: 7515: 7511: 7507: 7504: 7501: 7496: 7492: 7488: 7485: 7480: 7476: 7470: 7466: 7459: 7456: 7450: 7446: 7440: 7417: 7413: 7409: 7404: 7400: 7376: 7356: 7345: 7344: 7333: 7329: 7325: 7322: 7318: 7313: 7309: 7304: 7300: 7296: 7292: 7288: 7283: 7278: 7274: 7270: 7267: 7263: 7259: 7256: 7253: 7249: 7245: 7240: 7236: 7232: 7229: 7226: 7222: 7217: 7213: 7208: 7204: 7178: 7174: 7150: 7146: 7142: 7137: 7133: 7112: 7108: 7104: 7099: 7095: 7083: 7082: 7071: 7068: 7065: 7062: 7057: 7052: 7047: 7044: 7041: 7036: 7031: 7026: 7023: 7017: 7014: 7008: 7004: 6998: 6995: 6992: 6989: 6986: 6983: 6978: 6971: 6968: 6961: 6958: 6955: 6950: 6946: 6939: 6936: 6930: 6926: 6920: 6900: 6897: 6894: 6890: 6886: 6881: 6877: 6873: 6870: 6866: 6862: 6857: 6853: 6832: 6828: 6824: 6819: 6815: 6811: 6808: 6804: 6800: 6795: 6791: 6770: 6766: 6762: 6757: 6753: 6732: 6729: 6726: 6722: 6718: 6713: 6709: 6688: 6684: 6680: 6675: 6671: 6659: 6648: 6645: 6640: 6636: 6632: 6627: 6623: 6619: 6614: 6610: 6606: 6603: 6600: 6597: 6594: 6589: 6584: 6579: 6576: 6573: 6568: 6563: 6558: 6555: 6549: 6546: 6540: 6536: 6530: 6527: 6524: 6521: 6518: 6515: 6510: 6503: 6500: 6493: 6490: 6487: 6482: 6478: 6471: 6468: 6462: 6458: 6452: 6433: 6432: 6421: 6416: 6412: 6408: 6405: 6400: 6396: 6392: 6389: 6363: 6359: 6355: 6350: 6346: 6325: 6321: 6317: 6312: 6308: 6287: 6283: 6279: 6274: 6269: 6264: 6259: 6254: 6226: 6221: 6217: 6213: 6210: 6207: 6203: 6197: 6193: 6189: 6186: 6183: 6179: 6175: 6170: 6166: 6162: 6159: 6155: 6151: 6146: 6139: 6136: 6121: 6120: 6109: 6106: 6103: 6098: 6094: 6090: 6085: 6080: 6075: 6072: 6069: 6064: 6059: 6054: 6051: 6045: 6042: 6036: 6032: 6026: 6021: 6017: 6013: 6010: 6007: 6002: 5995: 5992: 5985: 5982: 5977: 5973: 5967: 5963: 5956: 5953: 5947: 5943: 5937: 5927: 5916: 5913: 5910: 5905: 5901: 5897: 5892: 5887: 5882: 5879: 5876: 5871: 5866: 5861: 5858: 5852: 5849: 5843: 5839: 5833: 5828: 5824: 5820: 5817: 5814: 5809: 5802: 5799: 5792: 5789: 5784: 5780: 5774: 5770: 5763: 5760: 5754: 5750: 5744: 5706: 5701: 5697: 5692: 5680: 5679: 5668: 5665: 5660: 5656: 5652: 5648: 5642: 5638: 5634: 5631: 5626: 5623: 5618: 5593: 5589: 5585: 5581: 5559: 5534: 5506: 5502: 5498: 5493: 5489: 5468: 5464: 5460: 5456: 5435: 5431: 5427: 5422: 5418: 5397: 5393: 5389: 5386: 5375: 5374: 5363: 5360: 5357: 5354: 5351: 5348: 5345: 5341: 5337: 5334: 5331: 5326: 5322: 5318: 5315: 5312: 5309: 5303: 5300: 5294: 5290: 5284: 5258: 5254: 5250: 5245: 5241: 5220: 5216: 5212: 5207: 5203: 5182: 5178: 5174: 5169: 5165: 5140: 5136: 5132: 5127: 5123: 5102: 5098: 5094: 5089: 5085: 5063: 5050: 5047: 5035: 5034: 5023: 5020: 5017: 5014: 5011: 5008: 5005: 5002: 4992: 4988: 4984: 4979: 4975: 4971: 4968: 4965: 4961: 4957: 4952: 4948: 4944: 4941: 4937: 4933: 4928: 4924: 4920: 4911: 4907: 4881: 4876: 4872: 4855: 4838: 4833: 4829: 4805: 4801: 4797: 4791: 4788: 4783: 4779: 4776: 4772: 4768: 4763: 4759: 4744: 4743: 4732: 4727: 4722: 4717: 4712: 4707: 4702: 4697: 4694: 4689: 4675: 4671: 4667: 4662: 4656: 4652: 4647: 4640: 4635: 4632: 4628: 4621: 4617: 4611: 4608: 4603: 4598: 4592: 4585: 4582: 4577: 4572: 4565: 4561: 4555: 4551: 4547: 4544: 4539: 4535: 4531: 4527: 4521: 4517: 4512: 4508: 4502: 4497: 4493: 4488: 4485: 4481: 4477: 4473: 4466: 4463: 4458: 4454: 4440: 4439: 4428: 4422: 4418: 4414: 4408: 4405: 4400: 4396: 4393: 4389: 4385: 4380: 4376: 4368: 4364: 4360: 4356: 4350: 4346: 4341: 4337: 4328: 4324: 4319: 4316: 4312: 4308: 4304: 4297: 4294: 4289: 4285: 4279: 4274: 4270: 4266: 4262: 4256: 4252: 4247: 4241: 4238: 4234: 4229: 4222: 4219: 4214: 4210: 4185: 4181: 4158: 4155: 4151: 4128: 4124: 4120: 4116: 4110: 4106: 4101: 4095: 4092: 4088: 4083: 4077: 4073: 4069: 4049: 4046: 4042: 4039: 4029:The diagonal ( 4027: 4026: 4015: 4010: 4006: 4002: 3998: 3992: 3988: 3983: 3973: 3968: 3961: 3958: 3953: 3949: 3946: 3941: 3938: 3934: 3928: 3924: 3920: 3916: 3910: 3906: 3901: 3895: 3892: 3888: 3883: 3876: 3873: 3868: 3864: 3857: 3853: 3849: 3842: 3839: 3836: 3832: 3828: 3819: 3813: 3809: 3806: 3801: 3797: 3792: 3788: 3785: 3778: 3772: 3768: 3764: 3754: 3747: 3742: 3737: 3733: 3730: 3725: 3720: 3716: 3707: 3677: 3637: 3633: 3630: 3623: 3617: 3613: 3609: 3599: 3592: 3566: 3562: 3558: 3548: 3526: 3523: 3520: 3517: 3514: 3511: 3508: 3502: 3499: 3495: 3491: 3486: 3482: 3461: 3457: 3453: 3449: 3437: 3436: 3425: 3422: 3418: 3414: 3410: 3406: 3403: 3400: 3396: 3392: 3388: 3384: 3381: 3377: 3373: 3363: 3358: 3355: 3351: 3347: 3337: 3332: 3314: 3313: 3302: 3298: 3294: 3290: 3286: 3283: 3280: 3277: 3274: 3270: 3266: 3262: 3258: 3255: 3252: 3228: 3207: 3203: 3199: 3195: 3191: 3185: 3182: 3177: 3165: 3164: 3153: 3149: 3145: 3140: 3136: 3130: 3126: 3123: 3118: 3114: 3109: 3105: 3101: 3097: 3093: 3089: 3085: 3081: 3077: 3072: 3068: 3063: 3053: 3048: 3044: 3040: 3036: 3032: 3028: 3022: 3019: 3014: 3010: 3007: 3002: 2998: 2995: 2988: 2982: 2978: 2974: 2964: 2957: 2928: 2924: 2920: 2909: 2908: 2897: 2892: 2888: 2885: 2880: 2876: 2871: 2867: 2863: 2859: 2855: 2851: 2847: 2843: 2839: 2834: 2830: 2825: 2821: 2817: 2813: 2809: 2805: 2799: 2796: 2791: 2787: 2773: 2772: 2761: 2758: 2754: 2750: 2745: 2741: 2737: 2733: 2729: 2725: 2721: 2716: 2712: 2706: 2701: 2698: 2695: 2691: 2687: 2684: 2680: 2676: 2672: 2668: 2665: 2642: 2638: 2634: 2630: 2626: 2621: 2617: 2596: 2592: 2588: 2584: 2580: 2577: 2563: 2562: 2551: 2548: 2545: 2542: 2539: 2536: 2533: 2530: 2515: 2512: 2508: 2504: 2499: 2495: 2491: 2487: 2483: 2478: 2474: 2470: 2464: 2461: 2458: 2455: 2451: 2447: 2443: 2439: 2434: 2430: 2424: 2421: 2417: 2388: 2384: 2362: 2338: 2334: 2305: 2283: 2260: 2256: 2233: 2229: 2202: 2198: 2186: 2185: 2174: 2171: 2168: 2165: 2162: 2159: 2156: 2153: 2143: 2139: 2135: 2131: 2127: 2122: 2118: 2114: 2110: 2106: 2101: 2097: 2093: 2090: 2086: 2082: 2078: 2074: 2069: 2065: 2055: 2025: 2004: 2000: 1996: 1992: 1988: 1983: 1979: 1963: 1962: 1951: 1943: 1940: 1936: 1932: 1928: 1923: 1920: 1917: 1912: 1909: 1905: 1889: 1885: 1881: 1874: 1871: 1867: 1861: 1858: 1854: 1845: 1842: 1839: 1836: 1833: 1830: 1827: 1823: 1817: 1813: 1809: 1800: 1776: 1769: 1745: 1742: 1738: 1715: 1712: 1708: 1678: 1672: 1667: 1662: 1657: 1652: 1646: 1642: 1637: 1634: 1630: 1618:inertial frame 1605: 1602: 1597: 1594: 1590: 1586: 1581: 1578: 1574: 1570: 1565: 1562: 1558: 1554: 1551: 1546: 1541: 1536: 1533: 1529: 1508: 1503: 1498: 1493: 1490: 1486: 1474: 1473: 1462: 1456: 1451: 1447: 1438: 1434: 1430: 1426: 1418: 1414: 1410: 1407: 1398: 1383: 1380: 1376: 1369: 1365: 1359: 1355: 1346: 1343: 1340: 1336: 1332: 1325: 1322: 1318: 1314: 1307: 1304: 1301: 1297: 1293: 1286: 1283: 1279: 1273: 1269: 1261: 1258: 1255: 1251: 1247: 1241: 1236: 1232: 1226: 1223: 1215: 1211: 1207: 1204: 1195: 1180: 1179: 1162: 1158: 1149: 1145: 1142: 1124: 1123: 1110: 1101: 1098: 1095: 1091: 1087: 1082: 1078: 1074: 1071: 1067: 1063: 1058: 1054: 1050: 1047: 1043: 1039: 1034: 1030: 1007: 1004: 988: 987: 976: 972: 968: 965: 962: 959: 956: 952: 948: 945: 942: 939: 935: 931: 922: 918: 909: 905: 886: 856: 852: 848: 843: 839: 825:. This is the 818: 814:, one obtains 799: 769: 765: 761: 757: 753: 750: 739: 738: 727: 723: 719: 715: 711: 708: 699: 695: 692: 688: 684: 680: 676: 673: 670: 666: 662: 658: 654: 645: 624:clamped-nuclei 611: 600: 594:kinetic energy 571: 568: 565: 562: 559: 556: 553: 548: 541: 538: 535: 532: 529: 526: 523: 520: 517: 514: 509: 505: 499: 496: 493: 490: 487: 482: 450: 447: 444: 441: 438: 433: 411: 408: 382: 378: 357: 354: 349: 345: 320: 316: 312: 309: 306: 301: 297: 276: 272: 269: 264: 260: 208: 205: 185: 164: 155: 151: 142: 138: 129: 125: 116: 112: 103: 59:wave functions 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 8527: 8516: 8513: 8511: 8508: 8506: 8503: 8501: 8498: 8497: 8495: 8488: 8483: 8480: 8478: 8475: 8473: 8470: 8467: 8464: 8463: 8462: 8456: 8448: 8444: 8440: 8436: 8432: 8428: 8424: 8420: 8413: 8410: 8405: 8401: 8397: 8393: 8389: 8385: 8381: 8377: 8370: 8367: 8362: 8358: 8354: 8350: 8346: 8342: 8338: 8334: 8326: 8323: 8318: 8314: 8310: 8306: 8302: 8298: 8294: 8290: 8283: 8280: 8275: 8269: 8265: 8261: 8257: 8250: 8247: 8242: 8241: 8236: 8232: 8226: 8223: 8219: 8213: 8210: 8205: 8199: 8195: 8188: 8185: 8179: 8174: 8170: 8166: 8162: 8159:(in German). 8158: 8154: 8147: 8145: 8141: 8128: 8124: 8117: 8114: 8108: 8097: 8094: 8090: 8084: 8081: 8078: 8072: 8069: 8065: 8061: 8057: 8050: 8046: 8039: 8035: 8028: 8021: 8017: 8014: 8010: 8004: 8001: 7994: 7990: 7987: 7985: 7982: 7980: 7977: 7975: 7972: 7970: 7967: 7965: 7962: 7961: 7957: 7955: 7953: 7950: 7944: 7927: 7922: 7918: 7909: 7905: 7901: 7896: 7892: 7885: 7882: 7874: 7869: 7861: 7853: 7848: 7843: 7834: 7831: 7825: 7815: 7812: 7809: 7803: 7800: 7795: 7785: 7775: 7772: 7767: 7756: 7753: 7747: 7737: 7730: 7729: 7728: 7695: 7672: 7650: 7647: 7623: 7619: 7615: 7593: 7586: 7585: 7584: 7549: 7545: 7521: 7518: 7513: 7509: 7502: 7499: 7494: 7490: 7483: 7478: 7474: 7468: 7457: 7454: 7448: 7438: 7431: 7430: 7429: 7402: 7398: 7390:The function 7388: 7331: 7327: 7311: 7298: 7294: 7290: 7281: 7272: 7268: 7265: 7261: 7257: 7254: 7238: 7234: 7230: 7206: 7202: 7194: 7193: 7192: 7176: 7172: 7162: 7135: 7131: 7097: 7093: 7069: 7066: 7063: 7055: 7050: 7042: 7034: 7029: 7024: 7015: 7012: 7006: 6996: 6993: 6990: 6984: 6981: 6976: 6966: 6956: 6953: 6948: 6937: 6934: 6928: 6918: 6898: 6895: 6879: 6875: 6871: 6855: 6851: 6817: 6813: 6809: 6793: 6789: 6755: 6751: 6730: 6727: 6711: 6707: 6673: 6669: 6660: 6646: 6643: 6638: 6634: 6625: 6621: 6617: 6612: 6608: 6601: 6598: 6595: 6587: 6582: 6574: 6566: 6561: 6556: 6547: 6544: 6538: 6528: 6525: 6522: 6516: 6513: 6508: 6498: 6488: 6485: 6480: 6469: 6466: 6460: 6450: 6442: 6438: 6437: 6436: 6419: 6414: 6410: 6406: 6403: 6398: 6394: 6390: 6387: 6380: 6379: 6378: 6375: 6348: 6344: 6310: 6306: 6272: 6267: 6262: 6257: 6252: 6243:= 1, 2), and 6242: 6224: 6219: 6215: 6208: 6205: 6201: 6195: 6184: 6168: 6164: 6160: 6144: 6134: 6107: 6104: 6101: 6096: 6092: 6083: 6078: 6070: 6062: 6057: 6052: 6043: 6040: 6034: 6024: 6019: 6015: 6008: 6005: 6000: 5990: 5980: 5975: 5971: 5965: 5954: 5951: 5945: 5935: 5928: 5914: 5911: 5908: 5903: 5899: 5890: 5885: 5877: 5869: 5864: 5859: 5850: 5847: 5841: 5831: 5826: 5822: 5815: 5812: 5807: 5797: 5787: 5782: 5778: 5772: 5761: 5758: 5752: 5742: 5735: 5734: 5733: 5730: 5728: 5724: 5723:Hilbert space 5720: 5699: 5695: 5666: 5658: 5654: 5640: 5636: 5629: 5624: 5621: 5616: 5607: 5606: 5605: 5579: 5548: 5524: 5520: 5491: 5487: 5420: 5416: 5361: 5358: 5355: 5346: 5343: 5332: 5324: 5316: 5313: 5301: 5298: 5292: 5282: 5275: 5274: 5273: 5270: 5243: 5239: 5205: 5201: 5167: 5163: 5154: 5125: 5121: 5087: 5083: 5048: 5046: 5044: 5038: 5021: 5018: 5015: 5012: 5009: 5006: 5003: 5000: 4977: 4973: 4969: 4966: 4950: 4946: 4926: 4922: 4918: 4909: 4898: 4897: 4896: 4879: 4874: 4870: 4861: 4854: 4836: 4831: 4827: 4817: 4789: 4786: 4781: 4777: 4761: 4757: 4747: 4730: 4725: 4715: 4710: 4700: 4695: 4692: 4660: 4654: 4650: 4645: 4638: 4633: 4630: 4626: 4619: 4609: 4606: 4590: 4583: 4580: 4575: 4570: 4563: 4559: 4553: 4549: 4545: 4542: 4519: 4515: 4495: 4491: 4486: 4483: 4479: 4464: 4461: 4456: 4445: 4444: 4443: 4426: 4406: 4403: 4398: 4394: 4378: 4374: 4348: 4344: 4326: 4322: 4317: 4314: 4310: 4295: 4292: 4287: 4277: 4254: 4250: 4239: 4236: 4232: 4220: 4217: 4212: 4201: 4200: 4199: 4183: 4179: 4156: 4153: 4149: 4108: 4104: 4093: 4090: 4086: 4075: 4071: 4047: 4044: 4040: 4037: 4013: 3990: 3986: 3971: 3959: 3956: 3951: 3944: 3939: 3936: 3932: 3908: 3904: 3893: 3890: 3886: 3874: 3871: 3866: 3855: 3851: 3847: 3840: 3837: 3834: 3830: 3826: 3817: 3811: 3807: 3804: 3799: 3795: 3790: 3786: 3783: 3740: 3735: 3731: 3728: 3705: 3697: 3696: 3695: 3675: 3666: 3660: 3657: 3651: 3635: 3631: 3628: 3580: 3537:. The matrix 3524: 3521: 3518: 3515: 3512: 3509: 3506: 3500: 3484: 3480: 3472:has elements 3423: 3404: 3401: 3356: 3323: 3322: 3321: 3319: 3292: 3278: 3275: 3264: 3250: 3243: 3242: 3241: 3197: 3183: 3180: 3175: 3138: 3134: 3128: 3124: 3121: 3116: 3112: 3083: 3070: 3066: 3051: 3034: 3020: 3017: 3012: 3005: 3000: 2996: 2993: 2946: 2945: 2944: 2942: 2895: 2890: 2886: 2883: 2878: 2874: 2845: 2832: 2828: 2811: 2797: 2794: 2789: 2778: 2777: 2776: 2759: 2743: 2739: 2727: 2714: 2710: 2704: 2699: 2696: 2693: 2689: 2685: 2674: 2656: 2655: 2654: 2632: 2619: 2615: 2586: 2566: 2549: 2546: 2543: 2540: 2537: 2534: 2531: 2528: 2513: 2510: 2506: 2489: 2476: 2472: 2462: 2459: 2456: 2445: 2432: 2428: 2422: 2419: 2415: 2407: 2406: 2405: 2402: 2386: 2382: 2336: 2332: 2323: 2318: 2258: 2254: 2231: 2227: 2218: 2200: 2196: 2172: 2169: 2166: 2163: 2160: 2157: 2154: 2151: 2133: 2120: 2116: 2099: 2095: 2091: 2080: 2067: 2063: 2053: 2045: 2044: 2043: 2023: 1994: 1981: 1977: 1968: 1949: 1941: 1938: 1934: 1921: 1918: 1915: 1910: 1907: 1903: 1887: 1883: 1879: 1872: 1869: 1865: 1859: 1856: 1852: 1843: 1840: 1837: 1834: 1831: 1828: 1825: 1821: 1815: 1811: 1807: 1798: 1790: 1789: 1788: 1785: 1783: 1779: 1772: 1765: 1759: 1743: 1740: 1736: 1713: 1710: 1706: 1697: 1693: 1670: 1660: 1655: 1640: 1635: 1632: 1628: 1619: 1595: 1592: 1588: 1584: 1579: 1576: 1572: 1568: 1563: 1560: 1556: 1549: 1544: 1531: 1501: 1488: 1460: 1454: 1449: 1436: 1432: 1428: 1424: 1416: 1412: 1408: 1405: 1396: 1381: 1378: 1374: 1367: 1363: 1357: 1353: 1344: 1341: 1338: 1334: 1330: 1323: 1320: 1316: 1312: 1305: 1302: 1299: 1295: 1291: 1284: 1281: 1277: 1271: 1267: 1259: 1256: 1253: 1249: 1245: 1239: 1234: 1224: 1221: 1213: 1209: 1205: 1202: 1193: 1185: 1184: 1183: 1160: 1156: 1147: 1143: 1140: 1133: 1132: 1131: 1129: 1099: 1096: 1080: 1076: 1072: 1056: 1052: 1048: 1032: 1028: 1020: 1019: 1018: 1015: 1013: 1005: 1003: 1001: 997: 993: 963: 960: 957: 943: 920: 916: 907: 896: 895: 894: 892: 885: 880: 878: 874: 870: 841: 837: 828: 824: 817: 813: 809: 805: 798: 795: 791: 787: 783: 759: 748: 717: 706: 697: 693: 682: 671: 660: 643: 635: 634: 633: 632: 627: 625: 621: 617: 610: 606: 599: 595: 590: 588: 546: 507: 503: 471: 467: 422: 417: 409: 407: 405: 400: 398: 380: 376: 355: 352: 347: 343: 334: 318: 314: 310: 307: 304: 299: 295: 274: 270: 267: 262: 258: 248: 246: 241: 237: 232: 230: 226: 222: 221:energy levels 218: 214: 206: 204: 183: 162: 153: 149: 140: 136: 127: 123: 114: 110: 101: 92: 88: 85:In molecular 83: 79: 77: 73: 68: 64: 63:atomic nuclei 60: 56: 55:approximation 52: 48: 44: 40: 33: 19: 8487: 8460: 8422: 8418: 8412: 8379: 8375: 8369: 8336: 8332: 8325: 8292: 8288: 8282: 8255: 8249: 8238: 8225: 8217: 8212: 8193: 8187: 8160: 8156: 8131:. Retrieved 8126: 8116: 8096: 8083: 8071: 8063: 8059: 8048: 8044: 8037: 8033: 8026: 8019: 8015: 8003: 7989:Kohn anomaly 7945: 7942: 7687: 7536: 7389: 7346: 7163: 7084: 6440: 6434: 6376: 6240: 6122: 5731: 5681: 5522: 5518: 5376: 5271: 5152: 5052: 5039: 5036: 4859: 4852: 4818: 4748: 4745: 4441: 4028: 3665:Leibniz rule 3661: 3652: 3578: 3438: 3317: 3315: 3166: 2910: 2774: 2567: 2564: 2403: 2319: 2216: 2187: 1966: 1964: 1786: 1781: 1774: 1767: 1764:atomic units 1760: 1695: 1694:and nucleus 1691: 1475: 1181: 1127: 1125: 1016: 1009: 995: 989: 890: 883: 881: 876: 872: 822: 815: 807: 803: 796: 789: 785: 781: 740: 628: 623: 615: 608: 597: 591: 421:wavefunction 413: 401: 332: 249: 235: 233: 210: 158:nuclear spin 90: 89:, using the 87:spectroscopy 84: 80: 54: 50: 46: 36: 8468:(in German) 8101:dependence. 7949:Jahn–Teller 466:vibrational 132:vibrational 8494:Categories 8109:References 1006:Derivation 794:eigenvalue 470:rotational 240:eigenvalue 236:electronic 188:electronic 145:rotational 119:electronic 8447:0009-2614 8404:0021-9606 8361:0021-9606 8317:0009-2614 8235:Huang, K. 8009:electrons 7919:χ 7902:− 7883:η 7870:τ 7865:∇ 7859:∇ 7849:τ 7822:ℏ 7810:η 7801:− 7789:~ 7773:η 7764:∇ 7744:ℏ 7738:− 7712:Γ 7696:η 7667:Γ 7651:η 7642:Γ 7620:χ 7610:Γ 7594:χ 7568:Γ 7546:χ 7510:ξ 7500:− 7475:ξ 7465:∇ 7445:ℏ 7439:− 7399:ξ 7375:Γ 7355:Γ 7321:Γ 7299:τ 7295:⋅ 7277:Γ 7273:∫ 7266:− 7258:⁡ 7235:ξ 7225:Γ 7203:χ 7173:χ 7064:χ 7051:τ 7046:∇ 7040:∇ 7030:τ 7003:ℏ 6991:χ 6982:− 6970:~ 6954:χ 6945:∇ 6925:ℏ 6919:− 6896:∼ 6872:− 6810:∼ 6728:∼ 6708:ψ 6635:ψ 6618:− 6596:χ 6583:τ 6578:∇ 6572:∇ 6562:τ 6535:ℏ 6523:χ 6514:− 6502:~ 6486:χ 6477:∇ 6457:ℏ 6451:− 6411:ψ 6395:ψ 6388:χ 6268:τ 6253:τ 6216:τ 6192:ℏ 6138:~ 6093:ψ 6079:τ 6074:∇ 6068:∇ 6058:τ 6031:ℏ 6016:ψ 6006:− 5994:~ 5972:ψ 5962:∇ 5942:ℏ 5936:− 5900:ψ 5886:τ 5881:∇ 5875:∇ 5865:τ 5838:ℏ 5832:− 5823:ψ 5813:− 5801:~ 5779:ψ 5769:∇ 5749:ℏ 5743:− 5705:⟩ 5696:ζ 5664:⟩ 5655:ζ 5651:∇ 5637:ζ 5633:⟨ 5617:τ 5580:τ 5533:∇ 5417:ψ 5385:Ψ 5353:Ψ 5344:− 5330:Ψ 5317:τ 5311:∇ 5289:ℏ 5283:− 5013:… 4974:ϕ 4947:ϕ 4875:α 4832:α 4778:≈ 4716:− 4701:≡ 4651:χ 4620:α 4576:χ 4560:∑ 4526:⟩ 4516:χ 4487:α 4457:χ 4453:⟨ 4395:− 4355:⟩ 4345:χ 4318:α 4288:χ 4284:⟨ 4261:⟩ 4251:χ 4240:α 4213:χ 4209:⟨ 4180:χ 4157:α 4115:⟩ 4105:χ 4094:α 4072:χ 4068:⟨ 3997:⟩ 3987:χ 3952:χ 3948:⟨ 3940:α 3915:⟩ 3905:χ 3894:α 3867:χ 3863:⟨ 3841:α 3831:∑ 3827:− 3800:δ 3741:≡ 3519:… 3481:ϕ 3448:ϕ 3409:ϕ 3387:ϕ 3282:Ψ 3254:Ψ 3176:χ 3117:δ 3096:⟩ 3067:χ 3013:χ 3009:⟨ 3006:≡ 2879:δ 2858:⟩ 2829:χ 2790:χ 2786:⟨ 2740:ϕ 2711:χ 2690:∑ 2664:Ψ 2616:χ 2576:Ψ 2529:α 2514:α 2503:∂ 2473:χ 2469:∂ 2460:− 2429:χ 2423:α 2383:χ 2333:χ 2322:(LCAO-MO) 2255:χ 2228:χ 2197:χ 2164:… 2117:χ 2064:χ 1978:χ 1942:α 1931:∂ 1927:∂ 1919:− 1911:α 1873:α 1860:α 1826:α 1822:∑ 1812:∑ 1661:− 1641:≡ 1532:≡ 1489:≡ 1446:∇ 1413:∑ 1409:− 1335:∑ 1296:∑ 1250:∑ 1246:− 1231:∇ 1210:∑ 1206:− 1100:⋯ 1097:≪ 1073:≪ 1049:≪ 964:ϕ 944:ϕ 749:χ 707:χ 672:χ 547:ψ 508:ψ 481:Ψ 432:Ψ 67:electrons 8510:Max Born 8231:Born, M. 8133:2 August 8032:implies 8013:momentum 7958:See also 7312:′ 7291:′ 5547:gradient 5043:diabatic 4790:′ 4661:⟩ 4584:′ 4571:⟨ 4465:′ 4407:′ 4296:′ 4221:′ 4041:′ 3960:′ 3875:′ 3808:′ 3787:′ 3732:′ 3656:diabatic 3632:′ 3581:) terms 3184:′ 3125:′ 3021:′ 2997:′ 2887:′ 2798:′ 416:electron 72:Max Born 8427:Bibcode 8384:Bibcode 8341:Bibcode 8297:Bibcode 8165:Bibcode 7537:Having 5545:is the 829:(PES): 213:benzene 207:Example 8445:  8402:  8359:  8315:  8270:  8200:  7688:where 7347:where 6123:where 5571:, and 5377:where 3504:  741:where 331:(with 45:, the 7995:Notes 6843:, or 5682:Here 4858:(the 2775:with 1182:with 1128:exact 106:total 8443:ISSN 8400:ISSN 8357:ISSN 8313:ISSN 8268:ISBN 8198:ISBN 8135:2022 8043:) ≪ 6336:and 5231:and 5113:and 4681:with 1898:with 1773:and 1728:and 1342:> 1303:> 356:1296 211:The 65:and 41:and 8435:doi 8423:265 8392:doi 8380:111 8349:doi 8337:105 8305:doi 8293:265 8260:doi 8173:doi 8161:389 8062:/(2 8047:/(2 8036:/(2 7255:exp 4996:for 3694:as 2524:for 2147:for 2015:of 1391:and 616:not 315:876 296:126 275:244 259:162 61:of 37:In 8496:: 8441:. 8433:. 8421:. 8398:. 8390:. 8378:. 8355:. 8347:. 8335:. 8311:. 8303:. 8291:. 8266:. 8233:; 8171:. 8143:^ 8125:. 8025:≫ 7875:12 7854:12 7522:0. 7387:. 7070:0. 7056:12 7035:12 6647:0. 6588:12 6567:12 6374:. 6273:12 6258:12 6220:12 6084:12 6063:12 5891:12 5870:12 5729:. 5517:, 5446:, 2653:: 2401:. 2317:. 1784:. 1758:. 879:. 468:, 344:36 311:15 271:26 91:BO 53:) 51:BO 8449:. 8437:: 8429:: 8406:. 8394:: 8386:: 8363:. 8351:: 8343:: 8319:. 8307:: 8299:: 8276:. 8262:: 8206:. 8181:. 8175:: 8167:: 8137:. 8064:m 8060:p 8052:e 8049:m 8045:p 8041:n 8038:m 8034:p 8030:e 8027:m 8023:n 8020:m 8016:p 7928:. 7923:0 7915:) 7910:0 7906:u 7897:1 7893:u 7889:( 7886:= 7880:] 7862:+ 7844:2 7841:[ 7835:m 7832:2 7826:2 7816:i 7813:+ 7807:) 7804:E 7796:1 7786:u 7779:( 7776:+ 7768:2 7757:m 7754:2 7748:2 7715:) 7708:| 7703:q 7699:( 7673:, 7670:) 7663:| 7658:q 7654:( 7648:+ 7645:) 7638:| 7633:q 7629:( 7624:0 7616:= 7613:) 7606:| 7601:q 7597:( 7571:) 7564:| 7559:q 7555:( 7550:0 7519:= 7514:0 7506:) 7503:E 7495:0 7491:u 7487:( 7484:+ 7479:0 7469:2 7458:m 7455:2 7449:2 7416:) 7412:q 7408:( 7403:0 7332:, 7328:] 7324:) 7317:| 7308:q 7303:( 7287:q 7282:d 7269:i 7262:[ 7252:) 7248:q 7244:( 7239:0 7231:= 7228:) 7221:| 7216:q 7212:( 7207:0 7177:0 7149:) 7145:q 7141:( 7136:1 7132:u 7111:) 7107:q 7103:( 7098:0 7094:u 7067:= 7061:] 7043:+ 7025:2 7022:[ 7016:m 7013:2 7007:2 6997:i 6994:+ 6988:) 6985:E 6977:1 6967:u 6960:( 6957:+ 6949:2 6938:m 6935:2 6929:2 6899:0 6893:) 6889:q 6885:( 6880:2 6876:u 6869:) 6865:q 6861:( 6856:1 6852:u 6831:) 6827:q 6823:( 6818:2 6814:u 6807:) 6803:q 6799:( 6794:1 6790:u 6769:) 6765:q 6761:( 6756:2 6752:u 6731:0 6725:) 6721:q 6717:( 6712:2 6687:) 6683:q 6679:( 6674:2 6670:u 6644:= 6639:2 6631:) 6626:2 6622:u 6613:1 6609:u 6605:( 6602:i 6599:+ 6593:] 6575:+ 6557:2 6554:[ 6548:m 6545:2 6539:2 6529:i 6526:+ 6520:) 6517:E 6509:1 6499:u 6492:( 6489:+ 6481:2 6470:m 6467:2 6461:2 6441:i 6420:, 6415:2 6407:i 6404:+ 6399:1 6391:= 6362:) 6358:q 6354:( 6349:2 6345:u 6324:) 6320:q 6316:( 6311:1 6307:u 6286:) 6282:q 6278:( 6263:= 6241:k 6239:( 6225:2 6212:) 6209:m 6206:2 6202:/ 6196:2 6188:( 6185:+ 6182:) 6178:q 6174:( 6169:k 6165:u 6161:= 6158:) 6154:q 6150:( 6145:k 6135:u 6108:, 6105:0 6102:= 6097:1 6089:] 6071:+ 6053:2 6050:[ 6044:m 6041:2 6035:2 6025:+ 6020:2 6012:) 6009:E 6001:2 5991:u 5984:( 5981:+ 5976:2 5966:2 5955:m 5952:2 5946:2 5915:, 5912:0 5909:= 5904:2 5896:] 5878:+ 5860:2 5857:[ 5851:m 5848:2 5842:2 5827:1 5819:) 5816:E 5808:1 5798:u 5791:( 5788:+ 5783:1 5773:2 5762:m 5759:2 5753:2 5700:n 5691:| 5667:. 5659:k 5647:| 5641:j 5630:= 5625:k 5622:j 5592:) 5588:q 5584:( 5558:q 5523:E 5519:m 5505:) 5501:q 5497:( 5492:k 5488:u 5467:) 5463:q 5459:( 5455:u 5434:) 5430:q 5426:( 5421:k 5396:) 5392:q 5388:( 5362:, 5359:0 5356:= 5350:) 5347:E 5340:u 5336:( 5333:+ 5325:2 5321:) 5314:+ 5308:( 5302:m 5299:2 5293:2 5257:) 5253:q 5249:( 5244:2 5240:u 5219:) 5215:q 5211:( 5206:1 5202:u 5181:) 5177:q 5173:( 5168:2 5164:u 5153:E 5139:) 5135:q 5131:( 5126:2 5122:u 5101:) 5097:q 5093:( 5088:1 5084:u 5062:q 5022:, 5019:K 5016:, 5010:, 5007:1 5004:= 5001:k 4991:) 4987:R 4983:( 4978:k 4970:E 4967:= 4964:) 4960:R 4956:( 4951:k 4943:] 4940:) 4936:R 4932:( 4927:k 4923:E 4919:+ 4914:n 4910:T 4906:[ 4880:A 4871:P 4856:n 4853:T 4837:A 4828:P 4804:) 4800:R 4796:( 4787:k 4782:E 4775:) 4771:R 4767:( 4762:k 4758:E 4731:. 4726:A 4721:R 4711:i 4706:r 4696:A 4693:i 4688:r 4674:) 4670:r 4666:( 4655:k 4646:| 4639:3 4634:A 4631:i 4627:r 4616:) 4610:A 4607:i 4602:r 4597:( 4591:| 4581:k 4564:i 4554:A 4550:Z 4546:i 4543:= 4538:) 4534:r 4530:( 4520:k 4511:| 4507:] 4501:e 4496:H 4492:, 4484:A 4480:P 4476:[ 4472:| 4462:k 4427:. 4421:) 4417:R 4413:( 4404:k 4399:E 4392:) 4388:R 4384:( 4379:k 4375:E 4367:) 4363:r 4359:( 4349:k 4340:| 4336:] 4331:e 4327:H 4323:, 4315:A 4311:P 4307:[ 4303:| 4293:k 4278:= 4273:) 4269:r 4265:( 4255:k 4246:| 4237:A 4233:P 4228:| 4218:k 4184:k 4154:A 4150:P 4127:) 4123:r 4119:( 4109:k 4100:| 4091:A 4087:P 4082:| 4076:k 4048:k 4045:= 4038:k 4014:. 4009:) 4005:r 4001:( 3991:k 3982:| 3976:n 3972:T 3967:| 3957:k 3945:+ 3937:A 3933:P 3927:) 3923:r 3919:( 3909:k 3900:| 3891:A 3887:P 3882:| 3872:k 3856:A 3852:M 3848:1 3838:, 3835:A 3822:n 3818:T 3812:k 3805:k 3796:= 3791:k 3784:k 3777:) 3771:) 3767:R 3763:( 3758:n 3753:H 3746:( 3736:k 3729:k 3724:) 3719:R 3715:( 3710:n 3706:T 3680:n 3676:T 3636:k 3629:k 3622:) 3616:) 3612:R 3608:( 3603:n 3598:H 3591:( 3565:) 3561:R 3557:( 3552:e 3547:H 3525:K 3522:, 3516:, 3513:1 3510:= 3507:k 3501:, 3498:) 3494:R 3490:( 3485:k 3460:) 3456:R 3452:( 3424:. 3421:) 3417:R 3413:( 3405:E 3402:= 3399:) 3395:R 3391:( 3383:] 3380:) 3376:R 3372:( 3367:e 3362:H 3357:+ 3354:) 3350:R 3346:( 3341:n 3336:H 3331:[ 3318:K 3301:) 3297:r 3293:, 3289:R 3285:( 3279:E 3276:= 3273:) 3269:r 3265:, 3261:R 3257:( 3251:H 3227:r 3206:) 3202:R 3198:; 3194:r 3190:( 3181:k 3152:) 3148:R 3144:( 3139:k 3135:E 3129:k 3122:k 3113:= 3108:) 3104:r 3100:( 3092:) 3088:R 3084:; 3080:r 3076:( 3071:k 3062:| 3056:e 3052:H 3047:| 3043:) 3039:R 3035:; 3031:r 3027:( 3018:k 3001:k 2994:k 2987:) 2981:) 2977:R 2973:( 2968:e 2963:H 2956:( 2927:) 2923:r 2919:( 2896:, 2891:k 2884:k 2875:= 2870:) 2866:r 2862:( 2854:) 2850:R 2846:; 2842:r 2838:( 2833:k 2824:| 2820:) 2816:R 2812:; 2808:r 2804:( 2795:k 2760:, 2757:) 2753:R 2749:( 2744:k 2736:) 2732:R 2728:; 2724:r 2720:( 2715:k 2705:K 2700:1 2697:= 2694:k 2686:= 2683:) 2679:r 2675:, 2671:R 2667:( 2641:) 2637:R 2633:; 2629:r 2625:( 2620:k 2595:) 2591:r 2587:, 2583:R 2579:( 2550:, 2547:z 2544:, 2541:y 2538:, 2535:x 2532:= 2511:A 2507:R 2498:) 2494:R 2490:; 2486:r 2482:( 2477:k 2463:i 2457:= 2454:) 2450:R 2446:; 2442:r 2438:( 2433:k 2420:A 2416:P 2387:k 2361:R 2337:k 2304:R 2282:r 2259:k 2232:k 2201:k 2173:. 2170:K 2167:, 2161:, 2158:1 2155:= 2152:k 2142:) 2138:R 2134:; 2130:r 2126:( 2121:k 2113:) 2109:R 2105:( 2100:k 2096:E 2092:= 2089:) 2085:R 2081:; 2077:r 2073:( 2068:k 2058:e 2054:H 2028:e 2024:H 2003:) 1999:R 1995:; 1991:r 1987:( 1982:k 1967:K 1950:. 1939:A 1935:R 1922:i 1916:= 1908:A 1904:P 1888:A 1884:M 1880:2 1870:A 1866:P 1857:A 1853:P 1844:z 1841:, 1838:y 1835:, 1832:x 1829:= 1816:A 1808:= 1803:n 1799:T 1782:A 1777:A 1775:M 1770:A 1768:Z 1744:B 1741:A 1737:R 1714:j 1711:i 1707:r 1696:A 1692:i 1677:| 1671:A 1666:R 1656:i 1651:r 1645:| 1636:A 1633:i 1629:r 1604:} 1601:) 1596:z 1593:A 1589:R 1585:, 1580:y 1577:A 1573:R 1569:, 1564:x 1561:A 1557:R 1553:( 1550:= 1545:A 1540:R 1535:{ 1528:R 1507:} 1502:i 1497:r 1492:{ 1485:r 1461:. 1455:2 1450:A 1437:A 1433:M 1429:2 1425:1 1417:A 1406:= 1401:n 1397:T 1382:B 1379:A 1375:R 1368:B 1364:Z 1358:A 1354:Z 1345:A 1339:B 1331:+ 1324:j 1321:i 1317:r 1313:1 1306:j 1300:i 1292:+ 1285:A 1282:i 1278:r 1272:A 1268:Z 1260:A 1257:, 1254:i 1240:2 1235:i 1225:2 1222:1 1214:i 1203:= 1198:e 1194:H 1165:n 1161:T 1157:+ 1152:e 1148:H 1144:= 1141:H 1122:. 1109:R 1094:) 1090:R 1086:( 1081:2 1077:E 1070:) 1066:R 1062:( 1057:1 1053:E 1046:) 1042:R 1038:( 1033:0 1029:E 996:E 975:) 971:R 967:( 961:E 958:= 955:) 951:R 947:( 941:] 938:) 934:R 930:( 925:e 921:E 917:+ 912:n 908:T 904:[ 891:R 887:n 884:T 855:) 851:R 847:( 842:e 838:E 823:R 819:e 816:E 808:R 804:R 800:e 797:E 790:R 786:r 782:R 768:) 764:R 760:, 756:r 752:( 726:) 722:R 718:, 714:r 710:( 702:e 698:E 694:= 691:) 687:R 683:, 679:r 675:( 669:) 665:R 661:, 657:r 653:( 648:e 644:H 612:e 609:H 601:n 598:T 570:r 567:a 564:e 561:l 558:c 555:u 552:n 540:c 537:i 534:n 531:o 528:r 525:t 522:c 519:e 516:l 513:e 504:= 498:l 495:a 492:t 489:o 486:t 449:l 446:a 443:t 440:o 437:t 423:( 381:2 377:n 353:= 348:2 333:N 319:N 308:= 305:N 300:2 268:= 263:2 184:E 163:. 154:E 150:+ 141:E 137:+ 128:E 124:+ 115:E 111:= 102:E 49:( 34:. 20:)

Index

Born-Oppenheimer approximation
Born approximation
quantum chemistry
molecular physics
wave functions
atomic nuclei
electrons
Max Born
J. Robert Oppenheimer
spectroscopy
benzene
Schrödinger equation
energy levels
partial differential eigenvalue equation
computational complexity
eigenvalue
potential energy surface
computational chemistry
molecular dynamics
electron
wavefunction
vibrational
rotational
Hamiltonian operator
kinetic energy
molecular Hamiltonian
Coulomb potential
Schrödinger equation
eigenvalue
Schrödinger equation

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