Transferable total-energy parametrizations for metals: Applications to elastic-constant determination

In this work we present a method of fitting augmented-plane-wave energy bands and total-energy results for the fcc and bcc structures to a nonorthogonal tight-binding Hamiltonian from which the sum of the eigenvalues is derived, and to a simple pair potential that is designed to account for all the other terms of the total-energy expression. We have applied this method to calculate the elastic constants of the metals Rh, Pd, Ta, Ir, and Au, avoiding the expensive first-principles calculations of the distorted structures. We obtained very good agreement with both first-principles local-density-functional-theory calculations and experiment.