Inner-shell photoionization of free and confined Mg in the region of the 2p thresholds

Abstract

Photoionization of the free and confined Mg (Mg@C60) have been calculated in the vicinity of the inner-shell 2p thresholds using R-matrix at the Breit–Pauli R-matrix level with a particular emphasis on the various resonance series leading up to the two lowest inner-shell thresholds and the changes resulting from the confinement. For free Mg, the calculated resonance positions agree well with NIST values, and a number of new resonances are identified. For confined Mg, the calculation was done for various depths of the confining potential well in order to follow the trajectories of the resonances as a function of well depth. The results for the well depth corresponding to Mg@C60 showed that most of the resonances moved to higher photon energy, as a result of the confinement, but a few moved to lower energies. This phenomenology was found to result from the fact that the 3p, 3d and 4s excitations are trapped by the confining potential well, while the higher excitations were not.