Theoretical Evaluation of thegShift in the Alkali Metals, Li, Na, K, Rb, and Cs

The spherical-wave-expansion procedure has been used to solve, in the spherical-cell approximation, the one-electron Schrödinger equation containing the spin-orbit interaction, and the results have been used to evaluate the $g$ shift in Li, Na, K, Rb, and Cs. Convergence of the numerical work is clearly demonstrated. The cellular potential seen by the conduction electron has been taken to consist of a local ion-core potential plus the Hartree field of the other conduction electrons, assumed uniformly distributed. This model, with the choice of local potentials made in the text, yields calculated values in good agreement with observed values for Li, Na, and K. However, there is a large discrepancy between the results of this model and observation for Rb and Cs. Possible sources of this discrepancy are discussed.