Influence of interatomic potential and simulation procedures on the structures and properties of sodium aluminosilicate glasses from molecular dynamics simulations

Abstract

The effects of various simulation parameters such as interatomic potential, cooling rate, system size, and glass-formation procedures on the short and medium range structures of sodium aluminosilicate glasses were investigated using molecular dynamics simulations. Two widely used interatomic potentials: a fixed-charge pair-wise potential and a diffusive charge reactive potential (DCRP) were investigated. To provide validation of the simulation results, high energy X-ray and neutron diffraction studies of the sodium aluminosilicate glasses were performed. The results show that the reactive potential provides reasonable structures consistent with those from the fixed charge potentials and experiments. But the fixed charge potential is more robust in various glass forming procedures such as constant pressure, constant volume, and the QSQ method, while DCRP is more sensitive to the ensemble choice and thermal history. The DCRP potential, however, has the advantage to allow study glass-water interactions and interfacial behaviors.