Ab initio study of the polymerisation of cyclopentasilane

Abstract

The molecular structures and vibration modes of cyclopentasilane (Si₅H₁₀) have been examined by employing ab initio and density-functional methods. Three different structures of Si₅H₁₀ with different symmetries are analysed, and the results show that the envelope (C _s ) and the twist (C₂) forms have similar energies and that the planar form (D_5h ) is about 50 meV less stable than the C _s and C₂ forms. The excited-state potential energy surface of Si₅H₁₀ is performed using the CIS electronic energy calculation. The ring-open reaction of Si₅H₁₀ 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.

Keywords:

• ab initio calculation
• cyclopentasilane
• polymerisation

Acknowledgements

This research was partly supported by the Special Coordination Funds for Promoting Science and Technology commissioned by the MEXT, Japan, by the Special project QGTD.08.09 commissioned by the Vietnam National University, Hanoi, and by the Fundamental Research Project 103.02.111.09 commissioned by NAFOSTED, Vietnam.

The computations presented in this study were performed at the Center for Information Science, Japan Advanced Institute of Science and Technology.