With the ansatz that the ground state wave function for a helium-like atom is of the form of [Formula: see text], the optimal correlation function [Formula: see text] is determined. Here x and y are the distances of the electrons from the nucleus, while z is that between the electrons. The parameters α and β are determined by minimizing the energy of the system. The method is particularly useful for calculating quantities which are sensitive to the short-range electron–electron correlation.