Ethylene Molecule in a Gaussian Basis. II. Contracted Bases

Abstract

A self‐consistent‐field calculation on ground‐state ethylene was performed using a large (sp) Gaussian basis. An upper bound to the Hartree—Fock energy and a lower bound to the correlation energy were obtained. A SCF study was made using sets of ``contracted functions''—functions defined as linear combinations of Gaussians. It was found that orbital and total energies quite close to those of the large, straight Gaussian calculation can be obtained with contracted sets at a saving of computation time. These studies also furnished information about atomic‐orbital input to be used in a LCAO orbital calculation.