Ab initiotight binding

Abstract

Empirical tight binding has proven to be very popular in recent years on account of its computational efficiency and accuracy. However, it has limitations, notably the difficulties associated with fitting parameters and improving models when the desired accuracy cannot be achieved. In the light of this, a number of efforts have been made to derive tight-binding models from first principles. Here are described a number of formalisms based on density functional theory which span the range of approaches currently being used.