Charge and intracule densities in singly excited heliumlike ions

The variation of the charge and intracule densities of singly excited states of two-electron ions with respect to spin multiplicity, nuclear charge, degree of excitation, and angular momentum quantum number is studied systematically. The n 1S, n 3S, n 1P, n 3P, n 1D, and n 3D states with n=3–6 are considered for all the ions from He through Ne8+ using highly accurate explicitly correlated wave functions. Special attention is paid to spin multiplicity differences, that is differences between the densities of a pair of states arising from the same electron configuration of the same ion.