First-principles study of the thermally induced polymerization of cyclopentasilane

Abstract

The molecular structures and vibration modes of cyclopentasilane (Si 5H 10) have been examined by employing ab initio and density-functional methods. Three different structures of Si 5H 10 with different symmetries are analyzed, and the results show that the envelope (C s ) and the twist (C 2) forms have similar energies and that the planar form (D 5 h ) is about 50 meV less stable than the C s and C 2 forms. The ring-open reaction of Si 5H 10 is investigated in detail by using the first-principles molecular-dynamics simulation for screening the reaction pathways. The formation of Si–H–Si is found to play an important role in the ring-open reaction.