Ground state and electron-electron interaction energies of the atoms of chemical elements

Based on an analysis of handbook data on the ionization potentials of 28 elements, an expression is obtained which relates the following four fundamental characteristics of the atom: nuclear charge, number of electrons, atomic energy unit, and ground state energy. An equation is also obtained which relates the electron-electron repulsion energy in neutral atoms to the number of electrons and main quantum numbers. These relationships, which are extrapolated to all the elements of the periodic table, provide a way to determine the full ionization energy of any atom and to estimate the contribution of electron-electron interaction energy to the ground-state energy of an atom.