Magnetic Interaction In Many-Body Perturbation Theory (MBPT) And The Calculation Of The High Principle Rydberg Series For Sodium Atom

In this paper, a relativistic Hartree-Fock (RHF) equation was developed and used to evaluate the fine-structure intervals of Rydberg states for sodium atom. A discrete, finite and nearly complete numerical basis set was built by introducing an external potential. We have made some necessary improvements for the scheme of grid distribution method to make it more flexible to deal with the computational problems for high Rydberg atoms and the contracted states under the external potential. On the basis of previous work, this paper mainly study the magnetic correlation effect of the many-body perturbation in atom structure and give the correction expression for the single excited processes, which is the most important part in many-body perturbation effect associated with magnetic interaction. We calculated the fine-structure intervals for np (n=16-19,22-16) series of sodium atom by using this approach. It is clear that the evaluated results become more close to experimental values, when we take the magnetic correction into account, than those without the magnetic effect. The relative deviation comparing with the experiments does not exceed0.46%.