Calculation of orientation-dependent double-tensor moments for Coulomb-type intermolecular interactions

Abstract

A new derivation is presented for the orientation-dependent interaction tensors which describe the electrostatic interaction between two multipole or multipole polarizability distributions both given in their own molecule-fixed coordinate system. This derivation leads to an explicit equations that allows easy and direct evaluation of formulae for the components of the double-tensors and also for high ranks. Such an equation is given for the real, complex spherical, and cartesian moments. The formula is suitable for providing stable computer-generated expressions for tensor operators of any rank.