The approach to e(+)-e(-) interaction in jellium proposed by Gondzik and Stachowiak [1] proved to be simple numerically and leading to reasonable results. This is why it seemed to be particularly suited for generalizations to real solids, a problem which in spite of more than thirty years of research in this direction did not get yet a satisfactory solution. An obstacle up to now was the necessity to solve integro-differential equations in two dimensions [2]. After overcoming this difficulty we were able to compute e(+)-e(-) enhancement for core and valence electrons in lithium and for core electrons in other two-electrons core elements. nic results are compared to such simplifying guesses concerning this problem as the local density, the generalized gradient and the weighted density approximations.