title: Quasibound continuum states in SiF4 (D2A1) photoionization: photoelectron-vibrational coupling.
abstract: The authors report a fully vibrationally resolved photoelectron spectroscopy investigation of a nonplanar molecule studied over a range of excitation energies. Experimental results for all four fundamental vibrational modes are presented. In each case significant non-Franck-Condon effects are seen. The vibrational branching ratio for the totally symmetric mode nu1+ is found to be strongly affected by resonant excitation in the SiF4+ (D2A1) photoionization channel. This is shown to be the result of two distinct shape resonances, which for the first time have been both confirmed by theoretical calculations. Vibrationally resolved Schwinger photoionization calculations are used to understand the vibronic coupling for the photoelectrons, both using ab initio and harmonic vibrational wave functions.
authors.affiliation: Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255, USA.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Montuoro
authors.forename: Robert R
authors.initials: RR
authors.lastname: Lucchese
authors.forename: John D
authors.initials: JD
authors.lastname: Bozek
authors.forename: Aloke
authors.initials: A
authors.lastname: Das
authors.forename: E D
authors.initials: ED
authors.lastname: Poliakoff