  Energy levels of germanium, tin and lead together with their single, double
and triple ionized positive ions have been calculated using the $V^{N-M}$
approximation suggested in the previous work (Dzuba, physics/0501032) (M=4 -
number of valence electrons). Initial Hartree-Fock calculations are done for
the quadruply ionized ions with all valence electrons removed. The core-valence
correlations are included beyond the second-order of the many-body perturbation
theory. Interaction between valence electrons is treated by means of the
configuration interaction technique. It is demonstrated that accurate treatment
of the core-valence correlations lead to systematic improvement of the accuracy
of calculations for all ions and neutral atoms.
