Molecular dynamics of silicate glass structure

Abstract

This work studies the structure of silicate glasses by means of molecular dynamics simulation (MD). The structure of simulated alkali-silicate glasses was investigated using Q-species (Q") distribution where "Q" denotes SiO4 tetrahedra and n is number of bridging oxygen atoms. The structure of MD glass at room temperature shows much lower fraction of Q3 units than the structure of real glass. Nevertheless, it was confirmed that small alkali cations produce more extensive decrease of the Q3 amount of compared with larger alkali cations and that it is caused by their effort to surround themselves with NBO atoms. Silicate network defects {Si}5 present in MD glasses were discussed with respect to alkali concentration and cationic field strength of alkali modifiers.