Continious energy surface and accurate mass formula

It is shown that the nuclear binding energy may be described with high accuracy when th system of nuclei is divided into regions bounded bymagic (submagic)numbers of neutrons and protons. In each of the intermagic regions, the binding energy is represented by a quadratic function of Z and N. The parameters of the binding-energy formula are determined by minimizing the mean square deviation (σ) of the nuclear masses from the experimental values, taking account of the continuity of the energy surface at the intersection of boundaries of the regions. The formula obtained provides a description with mean square deviation σ =0,11 МeV for nuclei with Z and N ≥ 28; the accuracy is increased with increases in mass number (for heavy nuclei σ = 0.08 MeV).