ISSN:
1432-2234
Keywords:
Key words: All-valence electrons MO theory
;
AO orthogonalization effects
;
Alternant hydrocarbon pairing symmetry
;
Electronic transitions
;
Magnetic circular dichroism
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract. An approximate linear combination of orthogonalized atomic orbitals (LCOAO) all-valence electrons theory is described, based on a previously suggested partitioning of the Fock operator. Kinetic energy and penetration terms are evaluated explicitly in a Löwdin OAO basis, while two-electron repulsion terms are treated according to the conventional neglect of differential overlap (NDO) approximation. One-electron and penetration integrals are parameterized explicitly to predict approximate alternant pairing symmetry for the π-systems of benzene and napthalene. Application of the resulting LCOAO theory to a variety of alternant and non-alternant hydrocarbons demonstrates significant improvements in the prediction of MCD B-terms and transition moment directions, particularly for alternant (4N+2)- or 4N-perimeter π-systems for which traditional NDO procedures fail.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s002140050287
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