On the optimization of local linear response calculations of atomic properties

Abstract

It is shown that several relationships valid for exact or variational-perturbation theories hold also, under quite general conditions, for much simpler (local potential) theories based on variations of an ad hoc functional. Equations of motion, formulae for the f-sum rule, frequency-dependent polarizability- and shielding-tensors are derived. Scaling procedures are discussed. Numerical examples, with a Slater exchange potential, are given. It is shown that the use of a cut-off potential, as in previous calculations, is detrimental to the optimization procedure.