Electronic quadrupole moments of excited states and the charge wavefunction of the many-electron theory

Abstract

It is shown that the electronic quadrupole moment as a measure of the charge distribution in non-closed shell systems is given not by the Hartree-Fock wavefunction, ΦRHF, but by the “charge distribution wavefunction” (the “charge wavefunction”) of NCMET, ϑc. The electronic quadrupole moments, Θ, of Be 1 1s22s2p3p0, B I 1s22s22p 2p0, B I 1s22s2p24P, B I 1s22s2p22D, and CI 1s22p32D0 are calculated by the full charge wavefunctions of NCMET and the Hartree-Fock wavefunctions. In C II, RHF gives Θ = 0.0 while the NCMET values are Θ = 0.07726 for J = 52 and Θ = 0.05408 for J = 32. Where several l ≠ 0 orbitals are involved in the excited state, the RHF results can differ sizably from the accurate NCMET charge wavefunction results. Recent beam measurements of electronic quadrupole moments are pertinent to these conclusions.