Non-Resonant Breakdown of the Franck-Condon Approximation as Seen in Vibrational Branching Ratios

Abstract

SynopsisWe consider vibrational branching ratios in the valence photoionization of N 2 , CO, and XCN, with X=F, Cl, Br, and I. Non-resonant geometry dependence of the matrix elements is seen to lead to the breakdown of the Franck-Condon approximation. The geometry dependence can be due to changing molecular orbitals or changing nodal positions in the continuum wave functions.