Anisotropies of Compton profiles in nickel

Abstract

The Compton profiles of nickel are calculated using an ab initio, spin-polarized self-consistent linear combination of Gaussian orbitals band-structure method within the local-density-functional theory. The resulting anisotropies are compared with recent experimental results of Rollason et al. The present theoretical results, which include the correlation potential, show improved agreement with experiment as compared to an earlier exchange-only calculation, especially in the low- and high-momentum regions. However, the present accurate local-density results still overestimate the anisotropies significantly, indicating the inadequacy of the local-density-functional theory for calculating the ground-state electron momentum density.