Reconstructed Three‐Dimensional Valence Electron Momentum Density of Si from Compton Profile Measurements

Recently measured anisotropies of Si valence electron Compton profiles with the scattering vector in the [100], [110], and [111] direction are analyzed together with calculated anisotropies of the corresponding Compton profiles from a modified free electron model. From both sets of profiles the momentum density ϱ(p) is reconstructed. In comparison with the modified free electron model the experimental momentum density is strongly reduced in the vicinity of p =0.6 to 1.0 at. units along the [100] direction and enhanced mainly in the vicinity of p =1.1 at. units along the [110] direction. These main features of the reconstructed experimental momentum density are well reproduced by a pseudopotential band calculation of valence electron momentum densities along the [100], [110], and [111] directions. Also the influence of the orthogonalization term on the momentum density is estimated.