Variational Monte Carlo calculation of dynamic multipole polarizabilities and van der Waals coefficients of the PsH system - art. no. 024503

The first three dynamic multipole polarizabilities for the ground state of hydrogen, helium, hydride ion, and positronium hydride PsH have been comput ed using the variational Monte Carlo (VMC) method and explicitly correlated wave functions. Results for the static dipole polarizability by means of t he diffusion Monte Carlo method and the finite field approach show the VMC results to be quite accurate. From these dynamic polarizabilities van der W aals dispersion coefficients for the interaction of PsH with ordinary elect ronic systems can be computed, allowing one to predict the dispersion energ y for the interaction between PsH and less exotic atoms and molecules.