  Ab initio QED calculations of the ground-state binding energies of
berylliumlike ions are performed for the wide range of the nuclear charge
number: Z=18-96. The calculations are carried out in the framework of the
extended Furry picture starting with three different types of the screening
potential. The rigorous QED calculations up to the second order of the
perturbation theory are combined with the third- and higher-order
electron-correlation contributions obtained within the Breit approximation by
the use of the large-scale configuration-interaction Dirac-Fock-Sturm method.
The effects of nuclear recoil and nuclear polarization are taken into account.
The ionization potentials are obtained by subtracting the binding energies of
the corresponding lithiumlike ions. In comparison with the previous
calculations the accuracy of the binding energies and the ionization potentials
is significantly improved.
