Intermolecular potential energy surfaces for the interaction between H 2 X (X O, S) and a metastable Ne * ( 3 P 2,0 ) atom

Stereodynamics in the Collisional Autoionization of Water, Ammonia, and Hydrogen Sulfide with Metastable Rare Gas Atoms: Competition Between Intermolecular Halogen and Hydrogen Bonds

“…[16,18,21] Briefly,f or V,a ni mproved Lennard-Jones function www.chemeurj.org has been used to represent the size repulsion (positive term) plus dispersion and induction attraction (negative term), and ac ombinationo fC oulomb contributions has been adopted to describe the electrostatic attraction/repulsion. [16,18,21] Briefly,f or V,a ni mproved Lennard-Jones function www.chemeurj.org has been used to represent the size repulsion (positive term) plus dispersion and induction attraction (negative term), and ac ombinationo fC oulomb contributions has been adopted to describe the electrostatic attraction/repulsion.…”

“…Such observables contain complementary information on the microscopic phenomena of interest. Specifically, they critically depend on the formation probability, energetics, structure, and lifetime of the intermediate collision complex (transition state), which evolves towards the final state of the ionic products 14–18. The present purpose is to emphasize, and rationalize, in a unifying picture, similarities and differences in the stereodynamics of all basic elementary processes involved.…”

“…Here, small moleculari ons interact with ac ompact Ne atom in the ground electronic state by the simple balance of size repulsion with induction/dispersion attraction. [16,18] This important experimental ob-servable is commonly named the "PIES energy shift" (see refs. Moreover,t he structure and positiono ft he measured peaks in PIES providem ore direct/unique information on the energetics of those configurations of the transition states that open the exit channels,l eading to the formation of product ions in as pecific electronic state.…”

“…The interaction formulation and the semiclassical method, have been presented in detail in some recent papers, [16,18,21] and only some basic aspectsa re discussed here (see below and next section). The interaction formulation and the semiclassical method, have been presented in detail in some recent papers, [16,18,21] and only some basic aspectsa re discussed here (see below and next section).…”

“…In the PIES experiments, such peaks are shifted with respect to the traditional photo‐ionization spectra, obtained under the same experimental conditions and taking into account the small energy difference between Ne* metastable atoms and Ne(I) photons,20 just for the energy stabilization of the collision complex owing to the effective intermolecular interaction 16. 18 This important experimental observable is commonly named the “PIES energy shift” (see refs. 16 and 20 and references therein).…”