Crystal Potentials Used in Energy Band Theory

Abstract

We have begun a study which has as its goal the determination of a good, one-electron, exchange-correlation operator for crystals. This paper contains preliminary results of eight, self-consistent field, AFW calculations performed for copper in the course of this work. We chose Cu because its electronic structure has been determined by several energy band methods, and also because relativistic and non-muffin tin effects are small in the crystal. In these computations all electronic states were calculated at each iteration. The core states (1s, 2s, 2p) were determined in the crystal field by a Herman-Skillman type program with boundary conditions, written by Snow. The innerband states (3s, 3p) were calculated at 32 points in the Brillioun zone via the APW program, and the band states (3d, 4s) were similarly calculated at 2048 points. Our self-consistent criterion was a maximum energy difference in the one-electron eigenvalues of 0.002 ry from one iteration to the next.