The spectral representation technique for an active-electron-only molecular orbital calculation applied to the case of nonspherical frozen charge

Abstract

The new approach, in which the interactions between the nonspherical dormant electrons and the active electrons are replaced with a kind of effective potential operator Veff, is introduced, taking a functional group COOH as a working example of the nonspherical dormant electron charges. To construct Veff, the use of the spectral representation technique is made. The validity of the new idea is tested by calculating the electronic structures of molecules H3C-COOH, H3C-CH2COOH, and H3C-CH2CH2COOH as a function of C-C bond length with use of Veff, and by comparing the results with those obtained by the all-electron calculations. The present approach is shown to be promising. The possibility of saving computation is also discussed. © 1993 American Institute of Physics.