Electronic density of states of fluid mixtures in the single superchain effective medium approximation

We introduce a straightforward extension to binary mixtures of Logan and Winn's formalism for the determination of the electronic density of states in disordered systems. Solutions obtained in the single superchain/effective medium approximation are also presented, and though reflecting the limitations intrinsic to the linear nature of this approximation, computer simulation results for the mixture of asymmetric hard spheres are reproduced quite satisfactorily. In particular the dependence of the band shape (and the width of the band gap) on the particle size asymmetry is correctly accounted for. The implementation of efficient integral equation algorithms to deal with complex Ornstein-Zernike equations also constitutes one of the key contributions of this work and is therefore treated in depth. (C) 1996 American Institute of Physics.