Physically Sound Orthogonality Procedures for Atomic Physics Calculations

Abstract
A physically sensible orthogonality procedure for use in atomic calculations is described. For clarity we focus on the orthogonalization of ejected-election orbitals to bound target orbitals for calculation of single ionization of multielectron atoms. A simple application to electron ionization of helium is given to illustrate the general analytic properties of the procedure and its practicability.