Parameter Perturbation Method for Helium Ground State Energy Calculation

Abstract

The ground-state energy is one of the most important pieces of information for research in various fields such as spectroscopy. However, the exact calculation of the value turns out to be challenging, and some approximation methods are needed. This paper is mainly focused on one of the approximations, the parameter perturbation method, and tries to investigate how well the method works to the helium ground-state energy calculation by comparing the approximated results with the experimental result and finding the relationship between the accuracy of the approximation and the orders of perturbation. Other commonly used approximation methods such as perturbation theory and variational principle are also introduced for comparisons and discussions. The paper finds that the parameter perturbation method turns out to be a desirable approach to approximate the helium ground-state energy because the approximated result is relatively easy to calculate and will get extremely close to the experimental result only within a few orders of perturbation. Therefore, the parameter perturbation method could become one of the potential candidates that researchers can use to estimate the energy levels for helium.