Energy resonances and widths of the (2pns) 1 P and (2pnd) 1 P Rydberg series

We report accurate photoionization calculations of resonance energies and widths of the 2pns 1 P and 2pnd 1 P Rydberg series (n = 4‐25) of the Be-like ions (Z = 8‐18). Calculations are performed using the screening constant by unit nuclear charge (SCUNC) method. The results are analyzed in the framework of the standard quantum defect theory, as well as of the SCUNC-procedure, by evaluating the effective nuclear charge. The results for Na 7+ to Ar 14+ ions are believed to be the first theoretical data. Those for O 4+ , F 5+ and Ne 6+ ions compare well with the available theoretical results. The new data obtained may provide useful guidelines for future photoionization studies on Be-like ions with Z = 11‐18.