Atomic magnesium: Discrete and continuum spectrum properties from a valence-shellL2configuration-interaction calculation with polarization potential

The discrete and continuous spectrum of atomic magnesium below the 3p${\mathrm{}}^2$ ${\mathit{P}}^{\mathrm{o}}$ ionization threshold has been investigated by a valence-shell frozen-core ${\mathit{L}}^2$ configuration-interaction calculation with a phenomenological polarization potential. The results presented include positions of bound and autoionizing levels, oscillator strengths and radiative lifetimes, the ground-state one- and two-photon ionization cross sections, and several observables of interest for long-range interaction and Zeeman-effect studies. In particular, the two-photon ionization cross section is discussed in the near-threshold region, where one experimental result is available for comparison