Many-body perturbation theory of frequency-dependent polarizabilities and van der Waals coefficients: Application to H2O–H2O and Ar–NH3

Correlation contributions to the multipole moments and frequency dependent polarizabilities of molecules are described within the framework of time-dependent coupled Hartree–Fock and many-body perturbation theory. Computationally feasible expressions are given for the ‘‘true’’ correlation contributions to the multipole moments and frequency dependent polarizabilities. The polarizabilities of argon, ammonia and water and the van der Waals induction and dispersion coefficients of H2O–H2O and Ar–NH3 are presented.