TRANSFERABLE NONORTHOGONAL TIGHT-BINDING MODEL FOR SILICON

We present a transferable tight-binding model; the electronic band str uctures and density of states of silicon in several cubic forms are ob tained, within a nonorthogonal basis. We have fitted the nonorthogonal tight-binding model of silicon with a minimal (s, p) basis. Using a n umerical procedure, our parameters were fitted to LMTO band structures in different, crystalline phases of silicon (f.c.c., b.c.c,, s.c., an d h.c.p.). Such fits were performed tc, obtain a model that we judged to be accurate and should be applicable to many other systems. In addi tion to a very good fit to the electronic properties of Si in differen t bulk crystal structures our TB parameters describe very well the ela stic constants and the optical phonon frequency at the zone-center in crystalline silicon.