A molecular dynamics study on Ag_3SI lattice parameters evolution with temperature

摘要

Ag_3SI is one of Ag like superionic conductors which has a crystal structure of three distinct phases. It has a gamma phase with R3 space group below 157K and a beta phase with Pm~(-3) m space group between 157K and 519K. Ag_3SI exists in its alpha phase with Im3m space group between 519K and 829K. Structural properties of gamma, betta and alpha phases of Ag_3SI are investigated by molecular dynamics simulation, using the Vashistha-Rahman type potentials. Molecular dynamic simulation was performed in NVE and NPT ensembles at different temperatures, varying from 5K up to 1000K. The calculations revealed that lattice parameters of Ag_3SI are similar with the findings obtained through experimental data. The description of the pair distribution functions by molecular dynamics in all phases is in good agreement with neutron diffraction experiments.