Positron annihilation in copper

Electron momentum distribution in copper is studied through the angular correlation of positron annihilation radiation, by employing self-consistent linear combination of Gaussian orbitals bands structure method. The two-photon momentum density is presented and analysed through three dimensional plots and angular momentum decomposed contributions. Calculation of two-dimensional angular correlation has been carried out in the independent particle approximation. The results for the analysis using Lock, Crisp and West theorem and the reciprocal form factors are also presented. The present theoretical results are compared with the experimental ones wherever possible and the agreement in general, is good. (author). 49 refs., 6 figs., 3 tabs