THE DOUBLY-EXCITED STATE 2P(2)3P FOR 1-LESS-THAN-OR-EQUAL-TO-Z-LESS-THAN-OR-EQUAL-TO-4 - COULOMB HOLES DERIVED FROM EXPLICITLY CORRELATED WAVE-FUNCTIONS

Doubly-excited states (DES) of simple atoms involve, by comparison with the ground state, relatively slow moving electrons which should therefore be more responsive to electron correlation. Hence, for the 2p2 3P State, correlation effects have been analysed in detail in terms of Coulomb holes, partial Coulomb holes and [r12n] when 1 less-than-or-equal-to Z less-than-or-equal-to 4. Comparisons are made with the 1s2 1S ground state and with the singly-excited state 1s2p 3P. As for the lower states, each DES was described by an accurate explicitly correlated wavefunction. For each Z, a similarity of characteristics, but not of scale, is found between the DES results and those for the ground state. The Coulomb holes for the 1s2p 3P states have a significantly different shape. The correlation effect for each DES system exceeds that for the corresponding lower states examined here. By comparison with He and the positive ions, the effect for H-(2p2 3P) is massive. The diffuseness of the partial Coulomb hole for H enabled us to identify and account for distinct features which, it is felt, will constitute the basic components of correlation diagrams for other atomic 'double-occupancy' states.