  The two-electron self-energy contribution to the ground state energy of
heliumlike ions is calculated both for a point nucleus and an extended nucleus
in a wide interval of Z. All the two-electron contributions are compiled to
obtain most accurate values for the two-electron part of the ground state
energy of heliumlike ions in the range Z=20-100. The theoretical value of the
ground state energy of heliumlike uranium, based on currently available theory,
is evaluated to be -261382.9(8) eV, without higher order one-electron QED
corrections.
