Resonant energies <em>E<sub>di</sub></em> and natural widths Γ<sub><em>d</em></sub> (in eV)

<p><b>Table 2.</b> Resonant energies <em>E<sub>di</sub></em> and natural widths Γ<sub><em>d</em></sub> (in eV). The numbers in brackets are the experimental errors.</p> <p><strong>Abstract</strong></p> <p>Photoionization (PI) cross sections of the ground state 1s<sup>2</sup> 2s<sup>2</sup> 2p<sup>6</sup><sup>1</sup> S<sub>0</sub> of Ne-like Ar<sup>8+</sup>, Fe<sup>16+</sup>, Kr<sup>26+</sup> and Xe<sup>44+</sup> ions are calculated by using the Dirac atomic <em>R</em>-matrix code based on a fully relativistic <em>R</em>-matrix method. To analyze the detailed resonant structure, systematical calculations based on the multiconfiguration Dirac–Fock method are performed for the dominant 2s → <em>n</em>p resonant transitions, and the resonant energies, strengths and total natural widths are presented. The resonant structures and characteristics of the PI cross sections and resonance strengths along the Ne-like sequence are discussed with emphasis on the influence of relativistic effects. For the Ar<sup>8+</sup> ion, good agreement is found between the present results and available theoretical calculations and experimental data.</p>