Abstract
The researchers report on a new study of the x-ray photoabsorption spectrum of sodium near the K-edge, involving the calculations of the excitation energies and the excitation transition probabilities for K-shell and M-shell electron excitations transitions in atomic sodium. The calculations were carried out by employing the 'multi configuration Dirac-Fock method', Breit interactions and 'finite nuclear size corrections' are included in the calculations, the transition probabilities were convoluted into 'Breit-Wigner' line shapes, and single 1s photoionization was also taken into account. In addition, the [1s]np and the [1s3s]ns n ' p singlet-triplet energy splitting was calculated. Results of the calculations were compared with previous measurements of the photoabsorption spectrum of sodium near the K-edge, and a very good agreement was observed.