A new tool for the rapid estimation of charge distribution

✍ Scribed by John J. Houser; Gilles Klopman

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 758 KB
• Volume: 9
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/jcc.540090811

✦ Synopsis

A method has been developed which uses a rapid connectivity-based calculation to give a reasonable approximation of CNDO u and T charges for most carbons in saturated and unsaturated hydrocarbons. In this calculation an appropriately parameterized Del Re method is used to calculate the I T charges, and if the molecule is unsaturated, these charges are used to modify the diagonal elements in a Huckel matrix, reducing the normally exaggerated v charges. The CNDO charges are obtained from "single point" calculations, using optimized geometries derived from molecular mechanics. The Del ReiHuckel method is most reliable where steric and hyperconjugative effects are absent.