Application of variational Monte Carlo method to the confined helium atom

A new application of variational Monte Carlo method is presented to study the helium atom under the compression effect of a spherical box with radius ( r c ). The ground-state energies of the helium atom were calculated for different values of r c . Our calculations were extended to include Li + and Be 2+ ions. The calculations were based on the use of a compact accurate trial wave function with five variational parameters. To optimize variational parameters, we used the steepest descent method. The obtained results are in good agreement with previous results.