Effective pair interionic interactions in supercompressed helium

The effective pair interionic interaction has been calculated for liquid helium in the metallic state. The potential was found at the second order of the perturbation theory in the electron-ion interaction. Because the depth of the potential well depends heavily on the method of approximation of the exchange interaction and electron gas correlations, the calculations were performed for several approximations. The authors propose an original form of the approximation. The effective pair interionic potentials of metallic hydrogen and helium were compared. An assumption about the possibility of the existance of metallic helium after the removal of external pressure was made.