The band structure of aluminium II. The convergence of the orthogonalized plane wave method

Abstract Herman (1954) has found poor convergence of the secular equation in the orthogonal plane-wave method of calculating band structures. It is shown that the convergence depends critically on the choice of the atomic-like functions ϕt used in this method. A particular choice gives much better convergence, and also results in an exact formulation of the method that is nevertheless very simple. These two advantages, together with the rather general form assumed for the potential, have rendered the method much more useful than previous experience has indicated.