Correlations of two excited electrons

TLDR

The symmetry of the Schrödinger equation and its eigenfunctions, together with the predominance of radial over angular correlations, underlie the study of electron pair dynamics, and prior work on doubly excited helium, the hydrogen negative ion, and Wannier’s threshold law has highlighted the importance of these correlations, though full connections remain incomplete. Recent studies on alkaline earths and the helium negative ion are presented as a prelude to a renewed analysis and interpretation of optical spectra and electron collisions for atoms with partially filled valence shells, offering opportunities to observe strong correlations. Advances over the last twenty years are reported, emphasizing the description of correlations through the distribution of an electron pair’s wavefunction in configuration space.

Abstract

Advances over the last twenty years are reported, with the emphasis on describing correlations through the distribution of an electron pair's wavefunction in its configuration space. The symmetry of the Schrodinger equation and its eigenfunctions are thus viewed and found to be important. The radial correlations are more significant for the mechanics of the pair than the angular correlations. Connections with other approaches to the subject are described. Earlier studies concerning doubly excited helium and the hydrogen negative ion are related to Wannier's threshold law (1953) for ionisation by electron collision, but these two subjects are not yet fully connected. Recent studies on the alkaline earths and helium negative ion are described and viewed as a prelude to a renewed analysis and interpretation of the optical spectra and electron collisions for atoms with partially filled valence shells, which afford ample opportunity for the manifestation of strong correlations.