Fine-structure energy levels, oscillator strengths and lifetimes in Mn XIII

We have performed large scale CIV3 calculations of excitation energies from ground state for 98 fine-structure levels as well as of oscillator strengths and radiative decay rates for all electric-dipole-allowed and intercombination transitions among the fine-structure levels of the terms belonging to the (1s22s2 2p6)3s2 3p, 3s3p2, 3s23d, 3p3, 3s3p3d, 3p2 3d, 3s3d2, 3s2 4s, 3s2 4p, 3s24d, 3s2 4f and 3s3p4s configurations of Al-like manganese. These states are represented by very extensive configuration-interaction (CI) wavefunctions obtained with the CIV3 computer code of Hibbert. The important relativistic effects in intermediate coupling are incorporated by means of the Breit-Pauli Hamiltonian. In order to keep our calculated energy splittings as close as possible to the experimental values, we have made small adjustments to the diagonal elements of the Hamiltonian matrices. Our calculated excitation energies, including their ordering, are in excellent agreement with the available experimental results. From our radiative decay rates, we have also calculated radiative lifetimes of some fine-structure levels. Differences between our calculated lifetimes and those of Froese Fisher et al (2006 At. Data Nucl. Data Tables 92 607) for several fine-structure levels are discussed