Analysis of the polarization-dependent rate of associative ionization of radiatively excited Na(3p) atoms.

Abstract

Kircz, Morgenstern, and Nienhuis [Phys. Rev. Lett. 48, 610 (1982)] have measured the cross section for the associative ionization of partially oriented pairs of excited [(3p) $^{2}P_{3/2}$] sodium atoms. Here, we extract information from these data about the identities of the participating adiabatic Born-Oppenheimer states of ${\mathrm{Na}}_{2}$. It is definitely established that more than one of these states is involved. The greatest contributor is the X $^{1}\ensuremath{\Sigma}_{g}^{+}$ state with the dominant molecular-orbital configuration ${\ensuremath{\sigma}}_{g}^{2}$ (at small internuclear separations). It is highly probable that only one other state (either the $^{1}\mathrm{\ensuremath{\Sigma}}_{\mathrm{g}}^{+}$ or $^{3}\mathrm{\ensuremath{\Sigma}}_{\mathrm{g}}^{\mathrm{\ensuremath{-}}}$ state with the dominant molecular-orbital configuration ${\ensuremath{\pi}}_{u}^{2}$) is involved, but a small contribution from one state ${(}^{1}$${\ensuremath{\Pi}}_{u}$ or $^{3}\mathrm{\ensuremath{\Pi}}_{\mathrm{u}}$) with the configuration ${\ensuremath{\sigma}}_{g}$${\ensuremath{\pi}}_{u}$ cannot be unequivocally dismissed.