Semiempirical Molecular Orbital Calculations and Molecular Energies. A New Formula for the β Parameter

Coffey, Patrick; Jug, Karl

doi:10.1021/ja00804a600

Cited by 37 publications

(11 citation statements)

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“…(25) have been suggested, either as theoretically derived formulas such as Eq. (17) [24,53], or as purely empirical functions tailored to mimic k H lk in a local AAB system [27],…”

Section: Orthogonalization Eects On Integrals and Matrix Elementsmentioning

confidence: 99%

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Orthogonalization corrections for semiempirical methods

Weber

Thiel

2000

Theoretical Chemistry Accounts: Theory, Computation, and Modeli

396

248

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Based on a general discussion of orthogonalization effects, two new one-electron orthogonalization corrections are derived to improve existing semiempirical models at the neglect of diatomic differential overlap level. The first one accounts for valence-shell orthogonalization effects on the resonance integrals, while the second one includes the dominant repulsive core–valence interactions through an effective core potential. The corrections for the resonance integrals consist of three-center terms which incorporate stereodiscriminating properties into the two-center matrix elements of the core Hamiltonian. They provide a better description of conformational properties, which is rationalized qualitatively and demonstrated through numerical calculations on small model systems. The proposed corrections are part of a new general-purpose semiempirical method which will be described elsewhere

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“…(25) have been suggested, either as theoretically derived formulas such as Eq. (17) [24,53], or as purely empirical functions tailored to mimic k H lk in a local AAB system [27],…”

Section: Orthogonalization Eects On Integrals and Matrix Elementsmentioning

confidence: 99%

“…In previous work, orthogonalization corrections have already been proposed at all three levels of integral approximation (CNDO ± S 2 [23], SINDO [24], SINDO1 [25,26], and NDDO [27]). The present development goes beyond these previous attempts, which include corrections only for the one-center core Hamiltonian matrix elements.…”

Section: Introductionmentioning

confidence: 99%

Orthogonalization corrections for semiempirical methods

Weber

Thiel

2000

Theoretical Chemistry Accounts: Theory, Computation, and Modeli

396

248

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“…These are the integrals resulting from use of equations (2), (4), and (7), respectively. Slater rule exponents were used, and the value for FISClsC was taken as 11.31 a.u., as given by Zerner [3].…”

Section: (7)mentioning

confidence: 99%

Potential energy integrals in semiempirical MO methods

Coffey

1974

Int J of Quantum Chemistry

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“…Semiempirical methods usually contain various levels of zero differential overlap (ZDO) assumptions [50], the complete neglect of differential overlap (CNDO), the intermediate neglect of differential overlap (INDO), or the neglect of diatomic differential overlap (NDDO). We suggested that the atomic orbitals should be considered as orthogo-nalized and introduced orthogonalization corrections [51]. Orthogonalization corrections have now also been implemented on the MNDO level [521.…”

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confidence: 99%

Extension of semiempirical methods to simulation of surfaces

Jug

1996

Int. J. Quant. Chem.

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Various approaches for surface simulation are described. They are based on free, saturated, and embedded clusters, as well as periodic models. The features of semiempirical methods are reviewed and ideas for their improvement are discussed. Special features of the structure and stability of clusters are presented which are suitable for the transition to the solid state. Linear and nonlinear relationships for binding energies and bond lengths in dependence of the average coordination number are discussed. Finally, a systematic way for the simulation of adsorption at ion crystal surfaces by model clusters is suggested.

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Semiempirical Molecular Orbital Calculations and Molecular Energies. A New Formula for the β Parameter

Cited by 37 publications

References 1 publication

Orthogonalization corrections for semiempirical methods

Orthogonalization corrections for semiempirical methods

Potential energy integrals in semiempirical MO methods

Extension of semiempirical methods to simulation of surfaces

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