Quantum Monte Carlo study of the ground vibrational states of Ar2–6H2S clusters. A case of microsolvation

Using an ArH2S interaction potential derived from ab initio calculations, rigid body diffusion quantum Monte Carlo calculations have been carried out to obtain structural and energetic information for clusters of H2S with two to six argon atoms. The potential surfaces of each of the clusters exhibit multiple minima. The lowest-energy structures show a preference for argon atoms to surround H2S. Barriers between the lowest-lying minima tend to be small resulting in ground state rotational constants that differ from those of equilibrium structures by up to 100 MHz.