Vol 3 - Landau, Lifshitz - Quantum mechanics - non-relativistic theory (3ed., 1991) · Problem §69-1

The Atom

Physics — Landau & Lifshitz · ground-level-energy-helium-perturbation

Problem

Determine approximately the energy of the ground level of the helium atom and helium-like ions (a nucleus of charge

Z

and two electrons), regarding the interaction between the electrons as a perturbation.