Electron correlation energy in the ground state of the helium sequence

Abstract

The purpose of this work is to examine five trial wave functions for the helium atom and thehelium-like ions (He, Li+Be2+,….Ne8+).The comparisons between the trial wave function have been done in view of the calculated energy (E) and the electron–electron repulsion, for the atom and all the ions considered. The calculations show that as the wave function becomes more correlated, Ecorrincreases and the percentage error in energy calculation decreases, whereas this percentage, for all systems under study, decreases as Z increases. The best trial wave function in this work gives results closer to the experimental findings due to a reduction in electron–electron repulsion.