Non-empirical core-polarization effects on the optical properties of Mg(I): II. Bound - bound and bound - free one- and two-photon transitions up to the third ionization threshold

The optical properties of Mg(I) have been computed using a CI approach in which the multi-electron basis includes single and double excitations from the M shell plus single excitations from the Ne-like core. The orbital set is of type and comprises STO, hydrogenic plus spatial oscillating STOCOS functions. The continuum states have been obtained by solving a discretized integral equation for the K-matrix half on the energy shell. Oscillator strengths and radiative lifetimes for the discrete states of the , and manifolds have been computed together with one- and two-photon cross sections of the ground and the states evaluated in the LOPT approximation. The maximum energies reached were 0.005 au and 0.035 au below the 4s ionization threshold for one- and two-photon processes, respectively. All the quantities have been determined in both the velocity and the length gauge.