First Principle Molecular Dynamic Simulation of the Gexasxs100-2x Glasses

The chalcogenide glasses GexAsxSi100-2x (x = 25,33.3) have been simulated by first principle molecular dynamics simulation based on the density functional theory. The local structural evolution of the glasses is analysed using pair distribution functions, coordination numbers and bond-angle distribution methods. We find that the topological continuity of GeS2 is disrupted and a relatively more homogeneous Ge - As bonded network is formed as Ge atoms participate in Ge - As type metal-metal bonding with increasing x.