Effects of electron correlations on Compton profiles of Li and Na in the GW approximation

The occupation number densities N(k)s of Li and Na are obtained from a first-principle calculation of the spectral function within the GW approximation. The dielectric matrix needed to form the screened potential W is computed within the random-phase approximation. The Compton profiles (CPs) of Li and Na are computed using the N(k)s. The computed CPs are in very close agreement with the results of recent high-resolution CP experiments. The renormalization factors on the Fermi surface Z(F)s are estimated for Li along the three principal symmetry directions. Although the Z(F)s are significantly smaller compared to those obtained so far using jellium models: they compare well with those evaluated from recent experimental CPs.