A heuristic screening approach for atoms includingl-splitting

Summary  TheZ-expansion theory of Atomic Structure is supplemented with the inclusion of the external screening concept, calculated from a simplified version of the works of M. Kregar, where the two-body potential energy operators are split into the sum of effective one-body operators. The use ofZ- andN-dependent screening parameters instead of screening constants, gives a simplified Screened Hydrogenic Model which compares favourably with more sophisticated methods, specially for ionized atoms. The author of this paper has agreed to not receive the proofs for correction. Member of the Consejo Nacional de Investigaciones Cientificas y Tecnicas, Argentina, and Associate Member ICTP (Trieste, Italy).