Chain structure of liquid and amorphous selenium: tight-binding molecular-dynamics simulation

Tight-binding molecular-dynamics (TB-MD) simulation has been performed to s tudy the properties on the microscopic scale of liquid and amorphous seleni um at 375 and 760 K. Since a diagonalization of the tight-binding (TB) Hami ltonian matrix is time consuming calculation, we have made parallel computa tions in the simulation program to realize a long time simulation of 512 at oms up to the 10(5) time steps corresponding to the order of 10 ps. The res ult shows that the radial distribution function, which becomes zero at arou nd 0.275 nm, agrees with experiments and the dihedral angle distribution fu nction has a maximum around 0 degrees, a minimum at 30 degrees and a smalle r maximum around 100 degrees. This tendency differs from a previous study e ither by the tight-binding Monte Carlo (TB-MC) simulation or by the first p rinciple molecular-dynamics (MD) simulation. (C) 1999 Elsevier Science B.V. All rights reserved.