On the hamiltonian theory of the molecule-electromagnetic field system

Abstract

A critical analysis is made of an improved formalism for the discussion of the interaction of molecules with the electromagnetic field. We demonstrate explicitly that the unitary transformation used to generate the new formalism serves to eliminate possible intermolecular Coulomb energies in favour of interactions carried by the transverse field, but that the intramolecular Coulomb terms are retained so that the advantages of the Coulomb gauge formalism are maintained.