Accurate resonance-parameter approach to transition-metal band structure

The position E-d and width W of the d resonance are shown to be good physical parameters, in that the same pair of parameters (E-d = 0.540, W = 0.088 Ry) is capable of reproducing Wood's band structure of fee and bcc iron to within a rms error of 0.006 Ry. The energy levels were obtained by diagonalizing an improved hybrid nearly-free-electron-tight-binding model Hamiltonian that includes explicitly the nonorthogonality of the basis functions.