Simplified Cartesian Basis Model for Intrapolyad Emission Intensities in the tilde {A}--> tilde {X} Bent-To Transition of Acetylene Conference Paper uri icon


  • Abstract The acetylene emission spectrum from the trans-bent electronically excited tilde {A} state to the linear ground electronic tilde {X} state has attracted considerable attention because it grants Franck-Condon access to local bending vibrational levels of the tilde {X} state with large-amplitude motion along the acetylene rightleftharpoons vinylidene isomerization coordinate. For emission from the ground vibrational level of the tilde {A} state, there is a simplifying set of Franck-Condon propensity rules that gives rise to only one zero- order bright state per conserved vibrational polyad of the tilde {X} state. Unfortunately, when the upper level involves excitation in the highly admixed ungerade bending modes, nu_4'and nu_6', the simplifying Franck-Condon propensity rule breaks down--so long as the usual polar basis (with v and l quantum numbers) is used to describe the degenerate …

publication date

  • June 1, 2015