Theoretical study of the heats of formation of Si2Hn (n = 0-6) compounds and trisilane

Heats of formation for Si/sub 2/H/sub n/ (n = 0-6) species and Si/sub 3/H/sub 8/ were obtained from electronic structure calculations combined with empirical bond energy correction factors. Several transition states enthalpies were also obtained, including those for the decomposition of Si/sub 2/H/sub 6/ to H/sub 2/Si = SiH/sub 2/ (/sup 1/A/sub g/) + H/sub 2/ and the isomerization of H/sub 3/SiSiH to H/sub 2/Si = SiH/sub 2/ (/sup 1/A/sub g/). The calculated reaction enthalpies and activation energies yield some new insights into Si/sub 2/H/sub 6/ and Si/sub 2/H/sub 4/ decomposition reactions.