U D MISRA and S CHATURVEDI

Physics Department, Lucknow University, Lucknow 226 007, India

Abstract.

The paper describes a new method for the calculation of the Sommerfeld screening parameter s₁.  It requires neither the knowledge of the energy separations of spin doublet levels nor is it based on the application of the Hertz law. The only data required for the calculation are the experimental energy values of the level concerned for the series of elements belonging to the same subshell in which the element in the question is situated. As an illustration the values of s₁ are calculated for the L₁, L ₂ and L₃ levels for elements belonging to the 4f subshell and these are found to be in excellent agreement with those published earlier by Gokhale and Misra. The method brings out the constancy of  s₁(L₁ L₃) – s₁(L₁) in a natural way and may thus be regarded as providing theoretical explanation of the Hertz law.

Keywords:  Screening parameters; spin doublets; irregular doublets; subshell; energy values; Hertz law.

Pacs Nos. 32.30.Rj