A high-resolution Compton scattering study of Cu: experiment and theory

We present [100], [110] and [111] Compton profiles of Cu at a high momentum resolution of 0.12 au, together with the corresponding highly accurate ban d theory computations, The theoretical and experimental results are compare d and contrasted with focus on the shape and anisotropy of the profile. A r easonable overall picture of the ground state momentum density of Cu is add uced, and the deviations from the band theory predictions based on the loca l density approximation (LDA) are consistent with those found in recent hig h-resolution studies of Li and Be. This study provides further evidence tha t the high-resolution Compton techniques offers a unique window on electron correlation effects, and that a satisfactory description of the momentum d ensity in solids requires a treatment of correlation effects beyond the LDA framework. (C) 1999 Elsevier Science Ltd. All rights reserved.