ISSN:
0020-7608
Keywords:
Computational Chemistry and Molecular Modeling
;
Atomic, Molecular and Optical Physics
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
This work involves the derivation of approximate forms for the matrix elements of an ab initio π-electron molecular orbital theory. The result may be described as a complete neglect of differential overlap mathematical formalism plus σ-π exchange. The basis set of π atomic functions for these derivations is a set of approximate Löwdin orthogonalized atomic orbitals (LOAO's) produced by successive pairwise orthogonalization. Using these functions, we derive approximate equations for the one-electron integrals of molecular orbital theory, αμLOAO and βμνLOAO, which, for the first time, show the effects of overlap-coupling in a molecule. Many new methods of approximation enter the theory. There are approximate equations for π-electron, nuclear attraction potentials and for π-electron, σ-core repulsion potentials, all approximations are compared to more accurate calculations where possible. A mechanism is also included for testing the effects of σ-charge shifts upon the results of the π-electron calculations.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/qua.560100310
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