Configurations of H3+(H2)n clusters and their energies

The H-3(+) ion plays an important role in low temperature astrophysical and laboratory plasmas. It is considered as the initiator of many ion-molecule chemistries. Also its clusters with H-2 are quite interesting. We study configurations of the H-3(+)(H-2)(n) clusters for n = 1 up to n = 12 as a simple test system. Total energies for these structures, with zero point vibration corrections have been calculated. Stabilization energies (the differences between the energy of the cluster and the energy of the individual molecules) are given and where possible compared to experiment. Calculations have been performed with ab initio method using 6-311+G* molecular basis set. It follows that the H-3(+)(H-2)(n) clusters can be considered as a structure with a core of H-3(+) and two shells consisting of H-2 molecules. The most stable structure for the bigger n is with three molecules on the first shell and nine molecules on the second one. Influence of increasing of size of clusters on changing of IR spectrum is also discussed - especially for v(1) and v(2) frequencies.