Variational procedure for symmetry-adapted Wannier functions

Abstract

An alternative derivation of the basic variational principle for Wannier functions is presented and combined with the symmetry properties so as to obtain a generalisation of the equations given by Koster (1953). An LCAO procedure for the solution of these equations is discussed and the outcome of such a procedure is compared with the Bloch functions obtained from a conventional LCAO calculation of the band structure.