Gaussian Lobe Function Expansions of Hartree—Fock Solutions for the First-Row Atoms and Ethylene

Gaussian expansions of ground-state Hartree—Fock solutions for the first-row atoms are determined by a self-consistent-field minimization of atomic energies. Wavefunctions are constructed from a basis set designed primarily for use in molecular calculations which consists only of functions of the form exp(—ar2). Angular dependence is achieved by defining origins for the basis functions at points in space determined in part by the symmetry of the orbital to be expanded. A use of atomic information in molecular problems is discussed in a SCF treatment of the ethylene molecule.