Variational Calculations for Three?Body S?States with Coulomb Interactions

Abstract

A general purpose programme designed to deal economically with the S-states of arbitrary systems interacting only via the static Coulomb interactions is described. Its aim is to simplify the calculation of the matrices of arbitrary operators with respect to the basis chosen; 'these matrices are then available for use in a variety of variational calculations. A number of illustrative calculations are presented which yield both upper and lower bounds for the energy of some typical systems and expectation values for a number of operators.