Tight binding calculations of vibrational and thermal properties of amorphous silicon

ORAL

Abstract

By displacing atoms by different amounts and computing atomic forces within the NRL tight binding method we obtain all second order (harmonic) and some third order (anharmonic) coupling constants of a 1000 atom TB-relaxed Wooten CRN model of amorphous silicon. The harmonic force constant results allow us to study various properties including vibrational density of states, dynamic structure factors, specific heat and thermal conductivity within Kubo theory. We shall present results of these applications and compare to experiment and previous work based on the Stillinger Weber potential.

Authors

  • Joseph Feldman

    Naval Research Laboratory and George Mason University, Center for Computational Materials Science, Naval Research Laboratory, and School of Computational Sciences, George Mason University

  • Michael Mehl

    Naval Research Laboratory

  • Dimitris Papaconstantopoulos

    Naval Research Laboratory and George Mason University

  • Noam Bernstein

    Naval Research Laboratory