RANDOM PHASE APPROXIMATION RESPONSE OF MOLECULAR-SYSTEMS TO ELECTROMAGNETIC-FIELDS - A VERY PRELIMINARY INVESTIGATION OF CHOICE CRITERIA FOR SLATER-TYPE BASIS-SETS

The problem of assessing the reliability of approximate quantum mechanical procedures for the prediction of nonlinear electromagnetic properties of atomic and molecular systems subjected to intense external light sources usually faces the necessity of telescoping into the basis set employed a number of appropriate polarization orbitals so as to realize as effectively as possible practical completeness of the expansion set. Two possible choice criteria for generating polarization STOs usuable in random phase approximation (RPA) calculations of electric properties are suggested and their relevance explored on the basis of a preliminary application to the simple case of the helium atom.