Large-scale Multiconfiguration Dirac-Hartree-Fock Calculations for Astrophysics: C-like Ions from O iii to Mg vii

Abstract

<jats:title>Abstract</jats:title> <jats:p>Large-scale multiconfiguration Dirac–Hartree–Fock calculations are provided for the <jats:italic>n</jats:italic> ≤ 5 states in C-like ions from O <jats:sc>iii</jats:sc> to Mg <jats:sc>vii</jats:sc>. Electron correlation effects are accounted for by using large configuration state function expansions, built from sets of orbitals with principal quantum numbers <jats:italic>n</jats:italic> ≤ 10. An accurate and complete data set of excitation energies, wavelengths, radiative transition parameters, and lifetimes is offered for the 156 (196, 215, 272, 318) lowest states of the 2<jats:italic>s</jats:italic> <jats:sup>2</jats:sup>2<jats:italic>p</jats:italic> <jats:sup>2</jats:sup>, 2<jats:italic>s</jats:italic>2<jats:italic>p</jats:italic> <jats:sup>3</jats:sup>, 2<jats:italic>p</jats:italic> <jats:sup>4</jats:sup>, 2<jats:italic>s</jats:italic> <jats:sup>2</jats:sup>2<jats:italic>p</jats:italic>3<jats:italic>s</jats:italic>, 2<jats:italic>s</jats:italic> <jats:sup>2</jats:sup>2<jats:italic>p</jats:italic>3<jats:italic>p</jats:italic>, 2<jats:italic>s</jats:italic> <jats:sup>2</jats:sup>2<jats:italic>p</jats:italic>3<jats:italic>d</jats:italic>, 2<jats:italic>s</jats:italic>2<jats:italic>p</jats:italic> <jats:sup>2</jats:sup>3<jats:italic>s</jats:italic>, 2<jats:italic>s</jats:italic>2<jats:italic>p</jats:italic> <jats:sup>2</jats:sup>3<jats:italic>p</jats:italic>, 2<jats:italic>s</jats:italic>2<jats:italic>p</jats:italic> <jats:sup>2</jats:sup>3<jats:italic>d</jats:italic>, 2<jats:italic>p</jats:italic> <jats:sup>3</jats:sup>3<jats:italic>s</jats:italic>, 2<jats:italic>p</jats:italic> <jats:sup>3</jats:sup>3<jats:italic>p</jats:italic>, 2<jats:italic>p</jats:italic> <jats:sup>3</jats:sup>3<jats:italic>d</jats:italic>, 2<jats:italic>s</jats:italic> <jats:sup>2</jats:sup>2<jats:italic>p</jats:italic>4<jats:italic>s</jats:italic>, 2<jats:italic>s</jats:italic> <jats:sup>2</jats:sup>2<jats:italic>p</jats:italic>4<jats:italic>p</jats:italic>, 2<jats:italic>s</jats:italic> <jats:sup>2</jats:sup>2<jats:italic>p</jats:italic>4<jats:italic>d</jats:italic>, 2<jats:italic>s</jats:italic> <jats:sup>2</jats:sup>2<jats:italic>p</jats:italic>4<jats:italic>f</jats:italic>, 2<jats:italic>s</jats:italic>2<jats:italic>p</jats:italic> <jats:sup>2</jats:sup>4<jats:italic>s</jats:italic>, 2<jats:italic>s</jats:italic>2<jats:italic>p</jats:italic> <jats:sup>2</jats:sup>4<jats:italic>p</jats:italic>, 2<jats:italic>s</jats:italic>2<jats:italic>p</jats:italic> <jats:sup>2</jats:sup>4<jats:italic>d</jats:italic>, 2<jats:italic>s</jats:italic>2<jats:italic>p</jats:italic> <jats:sup>2</jats:sup>4<jats:italic>f</jats:italic>, 2<jats:italic>s</jats:italic> <jats:sup>2</jats:sup>2<jats:italic>p</jats:italic>5<jats:italic>s</jats:italic>, 2<jats:italic>s</jats:italic> <jats:sup>2</jats:sup>2<jats:italic>p</jats:italic>5<jats:italic>p</jats:italic>, 2<jats:italic>s</jats:italic> <jats:sup>2</jats:sup>2<jats:italic>p</jats:italic>5<jats:italic>d</jats:italic>, 2<jats:italic>s</jats:italic> <jats:sup>2</jats:sup>2<jats:italic>p</jats:italic>5<jats:italic>f</jats:italic>, and 2<jats:italic>s</jats:italic> <jats:sup>2</jats:sup>2<jats:italic>p</jats:italic>5<jats:italic>g</jats:italic> configurations in O <jats:sc>iii</jats:sc> (F <jats:sc>iv</jats:sc>, Ne <jats:sc>v</jats:sc>, Na <jats:sc>vi</jats:sc>, Mg <jats:sc>vii</jats:sc>). By comparing available experimental wavelengths with the MCDHF results, the previous line identifications for the <jats:italic>n</jats:italic> = 5, 4, 3 → <jats:italic>n</jats:italic> = 2 transitions of Na <jats:sc>vi</jats:sc> in the X-ray and EUV wavelength range are revised. For several previous identifications discrepancies are found, and tentative new (or revised) identifications are proposed. A consistent atomic data set including both energy and transition data with spectroscopic accuracy is provided for the lowest hundreds of states for C-like ions from O <jats:sc>iii</jats:sc> to Mg <jats:sc>vii</jats:sc>.</jats:p>