Paper XLIII

Transition probabilities for Fe V

S.N. Nahar, F. Delahaye, A.K. Pradhan, and C.J. Zeippen

Astronomy & Astrophysics Supplement Series, 2000, Vol.144, pp.141-155

An extensive set of dipole-allowed, intercombination, and forbidden transition probabilities for Fe V is presented. The Breit-Pauli R-matrix (BPRM) method is used to calculate $1.46 10^6$ oscillator strengths for the allowed and intercombination E1 transitions among 3865 fine-structure levels dominated by configuration complexes with $n \leq 10$ and $l \leq 9$. These data are complemented by an atomic structure configuration interaction (CI) calculation using the SUPERSTRUCTURE program for 362 relativistic quadrupole (E2) and magnetic dipole (M1) transitions among 65 low-lying levels dominated by the 3d$^4$ and 3d$^3$4s configurations. Procedures have been developed for the identification of the large number of fine-structure levels and transitions obtained through the BPRM calculations. The target ion Fe VI is represented by an eigenfunction expansion of 19 fine-structure levels of 3d$^3$ and a set of correlation configurations. Fe V bound levels are obtained with angular and spin symmetries $SL\pi$ and $J\pi$ of the (e+ Fe VI) system such that 2S+1 = 5, 3, 1, $L \leq$ 10, $J \leq 8$ of even and odd parities. The completeness of the calculated dataset is verified in terms of all possible bound levels belonging to relevant LS terms and transitions in correspondence with the LS terms. The fine-structure averaged relativistic values are compared with previous Opacity Project LS coupling data and other works. The 362 forbidden transition probabilities considerably extend the available data for the E2 and M1 transtions, and are in good agreement with those computed by Garstang for the 3d$^4$ transitions.