Self-terms of intermolecular force constants

Abstract

The self-terms of the intermolecular force constants are derived by employing the condition of translation invariance. The self-terms thus obtained ensure that the dynamical matrices of the crystal are always Hermitian. The role of the condition of rotation invariance is discussed. The expressions for the self-terms differ in part from those published by Dolling, Pawley & Powell [Proc. Roy. Soc. (1973). A333, 363-384]. The conditions under which the self-terms of these authors are identical with the present ones are discussed.