The structuring of a molecular dopant in a quantum solvent - OCS(H-2)(N) Van der Waals clusters

The structural features of a varying number of pH(2) molecules bound to one dopant molecule of OCS are examined using quantum calculations with the Diffusion Monte Carlo (DMC) approach. The interaction forces were obtained from ab initio calculations for the OCS-pH(2) system and for the pH(2) dimer. The overall potential energy surface is then constructed as a sum of interpartner potentials where the pH(2) molecules are treated as spherical species. The calculations suggest that PH2 molecules indeed behave as a quantum solvent and that all initial 'doughnut' of five to six equivalent pH(2) partners is formed on the bisecting middle plane perpendicular to the OCS main axis, showing there strong spatial delocalization. Further added molecules move sequentially to either end of the dopant species, a, process seen here to be increasingly more affected by the H-2-H-2 interactions contributing to clusters stability.