Ab initio molecular dynamics study of the reaction between Th(+) and H(2)O.

The gas phase reaction of Th(+) with H(2)O to produce HThO(+) + H and ThO(+) + H(2) was investigated using density functional theory and coupled cluster methods. RRKM calculations of the branching ratio favor the H atomic elimination channel in disagreement with experiment. Ab initio classical trajectory calculations were carried out to obtain a better model of the molecular dynamics. The molecular dynamics simulations yield a branching ratio of ca. 80% for the H(2) elimination channel to 20% for the H atomic elimination channel in qualitative agreement with the observed ratio of 65% to 35%.