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RECORD NUMBER: 59 OF 190

OLS Field Name OLS Field Data
Main Title Further Evaluation and Development of Charge Similarity Indices for Choosing Molecular Analogues (Journal Version).
Author Richard, A. M. ; Rabinowitz, J. R. ;
CORP Author Health Effects Research Lab., Research Triangle Park, NC.
Publisher 1988
Year Published 1988
Report Number EPA/600/J-88/197;
Stock Number PB89-119846
Additional Subjects Molecular structure ; Electron density(Concentration) ; Physiochemistry ; Comparisons ; Reprints ; Charge similarity index ; Ether/dimethyl ; Acetic acid/methoxy ; Intermediate neglect of differential overlap ; CNDO method ; Ab initio analysis
Holdings
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Status
NTIS  PB89-119846 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 03/14/1989
Collation 12p
Abstract
Two molecular charge similarity index (CSI) methods are further evaluated for practical application - one method based on a simple CNDO-type approximation to the electron density function and the other based on an ab-initio pseudo total charge density function. The test system consists of isosteric analogues of dimethyl ether and methoxy acetic acid. The effects of differences in skeletal structure on the CSI measure of electron density similarity about corresponding atoms is estimated and two new developments are presented for application of the ab-initio based methods: (1) an INDO-type approximation which improves the efficiency of the CSI calculation; and (2) a FOCUS feature which enables comparisons of local molecule regions.