title: Photodetachment anisotropy for mixed s-p states: 8/3 and other fractions.
abstract: An approximate model for analytical prediction of photoelectron angular distributions in anion photodetachment from mixed s-p states is presented. Considering the dipole-allowed s, p, and d free-electron partial waves, the model describes photodetachment anisotropy in terms of the fractional p character of the initial orbital and the A and B coefficients describing the relative intensities of the p → d to p → s and s → p to p → s channels, respectively. The model represents an extension of the central-potential model to an intermediate regime encompassing varying degrees of s and p contributions to the initial bound orbital. This description is applicable to a broad class of hybrid molecular orbitals, particularly those localized predominantly on a single atom. Under the additional assumption of hydrogenic or Slater-type orbitals, the B/A ratio in photodetachment from a mixed 2s-2p state is shown to equal 8/3. Corresponding fractions are derived for other ns-np mixing cases. The predictions of the model are tested on several anion systems, including NH(2)(-) and CCl(2)(-). The quantitative discrepancies in the latter case are attributed to the breakdown of the central-atom approximation and a mechanism for corresponding corrections is indicated.
authors: Department of Chemistry and Biochemistry, The University of Arizona, Tucson, Arizona 85721, USA. sanov@u.arizona.edu
authors: Andrei
authors: A
authors: Sanov
authors: Emily R
authors: ER
authors: Grumbling
authors: Daniel J
authors: DJ
authors: Goebbert
authors: Lori M
authors: LM
authors: Culberson