Inner-shell photoionization of atomic chlorine near the 2p$^{-1 }$ edge: a Breit-Pauli R-matrix calculation

An R-matrix calculation which takes into account relativistic effects via the Breit-Pauli (BP) operator is performed for photoionization cross sections of atomic Cl near the 2p threshold. The wavefunctions are constructed with orbitals generated from a careful large scale configuration interaction (CI) calculation with relativistic corrections using the CIV3 code of Hibbert [1] and Glass and Hibbert [2]. The results are contrasted with the calculation of Martins [3], which uses a CI with relativistic corrections, and compared with the most recent measurements [4]. [1] A. Hibbert, \textit{Comput. Phys. Commun. }\textbf{9, }141 (1975) [2] R. Glass and A. Hibbert, \textit{Comput. Phys. Commun. }\textbf{16, }19 (1978) [3] M. Martins, J. Phys. B \textbf{34}, 1321 (2001) [4] D. Lindle \textit{et al} (private communication) Research supported by U.S. DOE, Division of Chemical Sciences, NSF and CAU CFNM, NSF-CREST Program. Computing facilities at Queen's University of Belfast, UK and of DOE Office of Science, NERSC are appreciated. ~