Application of the Tersoff interatomic potential to pressure-induced polyamorphism of silicon

Molecular-dynamics simulations of the pressure-induced structural changes of amorphous Si have been performed using the Tersoff interatomic potential to examine the validity of this potential. Amorphous Si with a tetrahedral network was prepared by melt-quenching methods, and it was then compressed under isothermal-isobaric conditions. The changes of the atomic pair-distribution functions and static structure factors with increasing pressure were in agreement with those observed experimentally. The pressure-induced amorphous structures contained a short-range order similar to the beta-tin and Imma structures. These results suggest that the Tersoff potential is suitable for describing the structural changes of amorphous Si under high pressure. (C) 2019 The Japan Society of Applied Physics