Band structure for an sp3 liquid in the single superchain/effective medium approximation

Abstract

We present a single superchain/effective medium approximation calculation of the electronic density of states for an sp3 fluid in a tight-binding Hamiltonian approximation, with parameters roughly chosen to represent liquid Hg. Comparison with direct diagonalization of the Hamiltonian using quenched liquid configurations generated by molecular dynamics shows that the performance of the theory is more than acceptable for moderate to high densities. Localization is estimated from the inverse participation ratio calculated from the simulation an in a second order renormalized perturbation theory proposed by Winn and Logan. Analysis of the results indicate that by increasing density the metal nonmetal transition occurs well after the band crossing transition. The major weakness of the theory as far as the density of states is concerned can very likely be coped with by inclusion of nonlinear corrections. © 1996 American Institute of Physics.