[理论室学术报告] Variation of electron correlation effects with radial and angular momentum factors in atomic systems: A case study of Ca+
||Dr. B. K. Sahoo
Atomic, Molecular and Optical
Physical Research Laboratory
Navrangpura, Ahmedabad - 380009
It is extremely challenging to perform high precision calculations in atomic systems with more than three electrons. Often, approximate solutions are obtained by applying mean-field theories such as (Dirac)-Hartree-Fock (DHF) method. Usually, the neglected electron correlation contributions in the DHF method are either included by finite order perturbative approaches for less accurate calculations or using all order perturbative approaches like Green's function technique, configuration-interaction (CI) method, (relativistic) coupled-cluster methods for perform high precision calculations. In all these methods, finite size basis functions are typically used and methods are truncated at some levels depending on the availability of computational resources and demand in the accuracies of the theoretical results. However, it is strenuous to account for the numerical errors in these methods. Therefore, validity of a many-body method is basically tested by comparing theoretical calculations with the available experimental data in an atomic system. In this talk, we shall demonstrate how electron correlations depend on the radial and angular factors of different properties. Thus, good agreement of some theoretical calculations with the experimental values cannot really test capability of a method to carry out high precision calculations.