Chain structure of liquid selenium investigated by a tight-binding Monte Carlo simulation

Abstract

The structure of liquid and amorphous selenium has been investigated by a Monte Carlo computer simulation. The semiempirical model relies upon a tight-binding approximation of the cohesive energy. The excellent agreement of the pair correlation functions and structure factors computed at different temperatures with the experiments allows a detailed analysis of the structures. The fraction of twofold-coordinated atoms never exceeds 70%. This implies that, contrary to commonly reported ideas, the chains have to be quite short, of the order of five bonds per chain, forming a highly connected network.