Franck–Condon analysis of the photoelectron spectra of HCCl−: Considering Duschinsky effects

Franck–Condon analysis and spectral simulations were carried out on the HCCl ( X ˜ 1 A ′ ) ← HCCl - ( X ˜ 2 A ″ ) photo-detachment process. The theoretical spectra obtained by using CCSD/6-311+G(2p, d) values are in agreement with the observed one. Otherwise, the equilibrium geometry parameters, r(CCl) = 1.950 ± 0.002 Å of the X ˜ 2 A ″ state of HCCl− are derived, by using the spectral simulation and employing an iterative Franck–Condon (IF–C) analysis procedure. Furthermore, through the different methods, our best calculated electron affinity is 1.2106 eV, which is in fair agreement with the experimental value.