Exact Korringa-Kohn-Rostoker Energy-Band Method with the Speed of Empirical-Pseudopotential Methods

A first-principles method of energy-band calculation is described which combines the arbitrary precision of the Korringa-Kohn-Rostoker or Green's-function method with the computational efficiency and intuitive appeal of the empirical-pseudopotential method and combined-$d$-plane-wave interpolation schemes. Although developed here in the context of energy-band theory, the method can be applied to any problem for which multiple scattering theory is appropriate. An illustrative application is described in which the occupied valence bands of copper are evaluated to millirydberg accuracy at the rate of 20 general $\overrightarrow{\mathrm{k}}\text{'}\mathrm{s}$ per second (∼8 msec per solution) on an IBM $\frac{360}{91}$ computer.