An approximate molecular orbital theory of large molecules. General formalism and application to the sulphate ion and sulphur hexafluoride

Abstract

An approximate MO scheme for the calculation of molecular electronic structure of large molecules is proposed by the use of well defined approximations to simplify the Fock Hamiltonian. The empirical Wolfsberg–Helmholz scheme follows from the neglect of a number of terms in the formalism derived here. Calculations of the ground state of the sulphate ion and sulphur hexafluoride using this method yield results in satisfactory agreement with experiment and with other approximate schemes.