Extended transition rates and lifetimes in Al I and Al II from systematic multiconfiguration calculations^⋆

¹ Materials Science and Applied Mathematics, Malmö University, 20506 Malmö, Sweden
e-mail: asimina.papoulia@mau.se
² Division of Mathematical Physics, Lund University, Post Office Box 118, 22100 Lund, Sweden

Received: 3 July 2018
Accepted: 22 September 2018

Abstract

MultiConfiguration Dirac-Hartree-Fock (MCDHF) and relativistic configuration interaction (RCI) calculations were performed for 28 and 78 states in neutral and singly ionized aluminium, respectively. In Al I, the configurations of interest are 3s²nl for n = 3, 4, 5 with l = 0 to 4, as well as 3s3p² and 3s²⁶l for l = 0, 1, 2. In Al II, in addition to the ground configuration 3s², the studied configurations are 3snl with n = 3 to 6 and l = 0 to 5, 3p², 3s7s, 3s7p, and 3p3d. Valence and core-valence electron correlation effects are systematically accounted for through large configuration state function (CSF) expansions. Calculated excitation energies are found to be in excellent agreement with experimental data from the National Institute of Standards and Technology (NIST) database. Lifetimes and transition data for radiative electric dipole (E1) transitions are given and compared with results from previous calculations and available measurements for both Al I and Al II. The computed lifetimes of Al I are in very good agreement with the measured lifetimes in high-precision laser spectroscopy experiments. The present calculations provide a substantial amount of updated atomic data, including transition data in the infrared region. This is particularly important since the new generation of telescopes are designed for this region. There is a significant improvement in accuracy, in particular for the more complex system of neutral Al I. The complete tables of transition data are available at the CDS.