BAND STRUCTURE FOR AN SP(3) LIQUID IN THE SINGLE SUPERCHAIN EFFECTIVEMEDIUM APPROXIMATION/

We present a single superchain/effective medium approximation calculat ion of the electronic density of states for an sp(3) fluid in a tight- binding Hamiltonian approximation, with parameters roughly chosen to r epresent liquid Hg. Comparison with direct diagonalization of the Hami ltonian using quenched liquid configurations generated by molecular dy namics shows that the performance of the theory is more than acceptabl e for moderate to high densities. Localization is estimated from the i nverse participation ratio calculated from the simulation an in a seco nd 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. Th e major weakness of the theory as far as the density of states is conc erned can very likely be coped with by inclusion of nonlinear correcti ons. (C) 1996 American Institute of Physics.