Uniform quality gaussian basis sets for molecular calculations. II. C2 hydrocarbons

Abstract

AbstractThis investigation is a continuation of a study on the optimality of MO basis sets of Gaussian functions, when constructed from AO basis sets optimized for the neutral atom or for ions. A formal charge parameter Q is used to adjust AO basis sets to the molecular environment, by virtue of a simple quadratic equation. Calculations are performed on a series of seven C2 hydrocarbons (C2H2, C2H4, C2H6, C2H3+ (open), C2H3+ (bridged), C2H5+ (bridged), and C2H4− radical anion). A simple rule is formulated to give approximate values of the charge parameter Q.