Dynamic Polarizabilities and van der Waals Coefficients

Abstract

A simple two-point Pad\'e approximant of the dynamic polarizability is used to generate a variety of formulas for van der Waals coefficients including the Slater-Kirkwood formula for two-body interactions and the Midzuno-Kihara formula for three-body interactions. The mathematical properties of the approximant are examined. It is shown that some formulae are bounds of the actual value while others give remarkably accurate results.