Molecular dynamics simulation of vitreous state by ionic pair potentials

Structural models of a single component vitreous state were systematically developed using molecular dynamics simulations incorporating ionic pair potentials. The M-X (M is a cation and X is an anion) pair bond distance was constrained between 1.4Angstrom and 2.7A. The charge of the M ion ranged from 2 to 5. The structural models can be classified into two groups based on the atomic arrangement. In the structural models the coordination number around the M ion is nearly constant up to some maximum M-X distance whose value depends upon the coordination numbers. Conversely, the coordination number around the M ions increases with an increase of the M-X distance when the M-X distance exceeds this maximum value. It was found that the atomic arrangement in which the coordination number is almost constant, is more stable than the other types of atomic arrangements. These structural models correspond to several glassformers which can form the vitreous state with a single component. (C) 2004 Elsevier B.V. All rights reserved.