The structure and the thermochemical properties of the H_3~+(H_2)_n clusters (n = 8-12)

摘要

Ab initio calculations were performed for the H_3~+(H_2)_n clusters (n = 8-12), including cmplete optimiation of several isomers of the n = 1O cluster. Binding energies, enthalpies, and ionization potentials are calculated. Well defined patterns of chromism are predicted for the H_2 collective vibrations and for the H_3~+ breathing vibrations. The calculations for the n > 10 clusters allow us to understand their shell structure in terms of concentric spheres of H_2 molecules. The first and second shell have occupation numbers equal to 3 and 6, respectively, while for the third shell, this number is within the range 12-15.