Correlated one-body momentum density for helium to neon atoms

Starting from explicitly correlated wavefunctions, the one-body momentum de nsity, gamma ((p) over right arrow), and the expectation values [delta((p) over right arrow)] and [p(n)], with n = -2 to +3, have been obtained for th e atoms helium to neon. All the calculations have been carried out by using the Monte Carlo algorithm. An analysis of the numerical accuracy of the me thod has been performed within the Hartree-Fock framework. The effects of t he electronic correlations have been systematically studied by comparing th e correlated results with the corresponding Hartree-Fock ones.