RELATIVISTIC CONFIGURATION-INTERACTION CALCULATIONS FOR OPEN-SHELL ATOMIC SYSTEMS

A relativistic configuration interaction method, which can handle a ge neral class of open-shell multiplets as the reference configurations, has been developed by combining the open-shell matrix Dirac-Fock self- consistent field algorithm implemented by Koc and Ishikawa [Phys. Rev. A 49 (1994) 794] with the relativistic configuration interaction algo rithm of Kagawa et al. [Phys. Rev. A 44 (1991) 7092]. We employ basis sets of Gaussian-type functions to expand the large and small componen ts of Dirac four-spinors. Relativistic configuration interaction calcu lations are tested on the ground and low-lying excited states of He an d He-like ions.