Theoretical Investigation of Transition Probabilities for 2s22p2-2s2p3-2p4 of Ca XV, Fe XXI

Two different methods have been used for a theoretical investigation of the energy spectra as well as transition probabilities of 2s 22p 2-2s2p 3-2p 4 in the case of Ca XV and Fe XXI: the non-relativistic Hartree-Fock method with relativistic corrections in the Breit approximation and the first two orders of a perturbation expansion in powers of 1/Z. Calculations are made in intermediate coupling using LS basis functions. Eigen-functions and eigenvalues of the Hamiltonian considered as well as wave-lengths and transition probabilities are presented in tables. The data obtained show that both methods lead to results which are in good agreement with the available experimental information. The results given can be used for the identification of energy levels not yet observed.