LOCAL THEORY OF ELECTRONIC STRUCTURE OF EXTENDED SYSTEMS

We present a theory of local electronic structure that yields the local density of states n(r,E) and related quantities. The theory applies whether the electronic wave functions themselves are delocalized or not and requires a knowledge of the Hamiltonian only in the vicinity of r. Several simple examples are worked out with good results. Possible applications include periodic and non-periodic transition metal systems and large molecules. One of the most general characteristics of condensed matter, in its normal state, is that the electronic properties in the vicinity of a point r depend significantly on the electrostatic potential @(r ' ) at points r ' near r. This physical property of "locality " is not directly evident from the wave