Electron scattering in HCl: An improved nonlocal resonance model

Abstract

We present an improved nonlocal resonance model for electron-HCl collisions. The short-range part of the model is fitted to ab initio electron-scattering eigenphase sums calculated using the Schwinger multichannel method, while the long-range part is based on the ab initio potential-energy curve of the bound anion HCl − . This model significantly improves the agreement of nonlocal resonance calculations with recent absolute experimental data on dissociative electron attachment cross sections for HCl and DCl. It also partly resolves an inconsistency in the temperature effect in dissociative electron attachment to HCl present in the literature. Finally, the present model reproduces all qualitative structures observed previously in elastic scattering and vibrational-excitation cross sections.

Absolute angle-differential vibrational excitation cross sections for electron collisions with diacetylene

“…Direct dissociation in the σ symmetry is possible, however, and is doubtlessly the mechanism in saturated compounds which have no π * resonances. It may yield sizable cross sections, as, for example, in HBr or HCl [57], where both VE and DEA are well understood theoretically [58,59]. On the other hand, the mechanism of low-energy DEA to unsaturated compounds which have a sizable dipole moment, where both a π * resonance and a dipole-bound resonance may be present and could act as a doorway state, is still being discussed [60][61][62][63][64].…”

Resonances and Dissociative Electron Attachment in HNCO

“…Figure 2(b) demonstrates that the dynamics is essentially one dimensional and that it will proceed mainly along the N─H bond. The curve-crossing behavior resembles situation in hydrogen halides, where the nonlocal model was successful in the qualitative and quantitative DEA description [11,12]. The central assumption of the nonlocal resonance model is that all the nonadiabatic coupling responsible for the DEA can be described in a diabatic representation represented by one discrete state jϕ d i crossing into the continuum of electron scattering states jϕ ϵ i.…”

“…In these, the resonance width is additionally a function of the electron energy. Both methods have been successful in reproducing phenomena resulting from the nonlocal and nonadiabatic effects [11,12]. However, in the case of DEA, they have been developed only for one-dimensional problems.…”

Division Xii / Commission 14 / Working Group Collision Processes

“…Dissociative processes: H 2 (Celiberto et al 2009, Bellm et al 2010, Celiberto et al 2011, HCl (Fedor et al 2010), HCl, DCl, HBr, DBr (Fedor et al 2008), C 2 H 2 (Chourou & Orel 2008). (Halmová et al 2008).…”