NATURAL EXPANSIONS OF CI WAVE-FUNCTIONS AND ANALYSIS OF COULOMB CORRELATIONS FOR HE(2P(2) P-3)-LIKE IONS

Natural expansions are presented for energetically acceptable configur ation-interaction (CI) wavefunctions for the He(2p2 3P)-like ions when 1 less-than-or-equal-to Z less-than-or-equal-to 4. The symmetry of th e natural orbitals and their occupation numbers are contrasted with ex isting results for the ls2 1S ground state. Moreover, results are give n for Coulomb holes, partial holes and interparticle expectation value s [r12n], where -2 less-than-or-equal-to n less-than-or-equal-to + 2. Comparisons are made with recently reported findings when the 2p2 3P s tates were described by 'benchmark' explicity-correlated (EC) wavefunc tions. The natural expansions of the CI functions allowed us to explor e the origin and convergence of the effects of Coulomb correlation. In particular, the analysis also highlighted significant changes in the relative importance of angular and radial correlation for these doubly -excited states as Z was increased.