Electron momentum density and Compton profiles in lithium along 〈100〉, 〈110〉, and 〈111〉 directions are calculated using full-potential linear augmented plane-wave basis within the generalized gradient approximation. The profiles have been corrected for correlations with the Lam-Platzman formulation using self-consistent charge density. The first and second derivatives of the Compton profiles are studied to investigate the Fermi-surface breaks. Decent agreement is observed between recent experimental values and our calculated values. Our values for the derivatives are found to be in better agreement with experiments than earlier theoretical results. The two-photon momentum density and one- and two-dimensional angular correlations of positron annihilation radiation are also calculated within the same formalism, and include the electron-positron enhancement factor.

• Received 2 November 1998

DOI:https://doi.org/10.1103/PhysRevB.60.10770