The Elastic Scattering of Electrons by Neutral Hydrogen Atoms by the Variational Method

Two variational methods are proposed for computing the phase shifts for an electron scattered by a neutral atom. These methods are shown to be different formulations of the same physical principle, i.e., the stationary property of the phase shift. By applying one of these methods to the $S$ scattering of an electron by a hydrogen atom, the phase shifts are computed for various kinetic energies. A comparison is finally made with the results which Morse and Allis have derived from the solution of the Fock equation.