Adsorption of HF and HCl molecules on ice at 190 and 235 K from molecular dynamics simulations: Free energy profiles and residence times

Abstract

Articles you may be interested inFree energy profiles for penetration of methane and water molecules into spherical sodium dodecyl sulfate micelles obtained using the thermodynamic integration method combined with molecular dynamics calculations

Photodissociation of a HCl molecule adsorbed on ice at T=210K

“…3 represents the tilt angle distribution function P(h) at the considered temperature and collected over the MD production period. It exhibits a well-defined peak centered around the value 118°, characteristic of a preferential tilted orientation in which the hydrogen atom of HCl points toward the ice surface in order to form a H bond with a dangling oxygen atom of the surface as already evidenced elsewhere [44,47]. Note that this distribution exhibits a small shoulder for a h angle close to 30°corresponding to the H atom pointing upwards.…”

“…It has been shown that the first layer behaves as a quasi liquid layer at 210 K [13,14]. More details on this ice description can be found in previous papers [44,45].…”

“…The main characteristics of our classical simulation have been already detailed in a previous paper [44]. They are briefly summarized here.…”

“…In the present calculation, the model surface is the (0 0 0 1) basal plane of a proton ordered hexagonal ice slab [44]. At 0 K, the surface layer is characterized by unsaturated H and O atoms, also called dangling atoms.…”

Evidence for distributed gas sources of hydrogen halides in the coma of comet 67P/Churyumov–Gerasimenko

“…Depending on the degree of ordering of the halogens in the water ice matrix, one can equivalently describe this configuration in terms of water complexes of the form H 2 O·HCl (formation of hydrates as discussed by Delzeit et al 1993) which decay as temperature goes up, in a process reminiscent of hydrated minerals (similar to hydrated halite). HF is similarly characterized by ionic adsorption onto water ice, although it is smaller and more easily accommodated in the water ice matrix (Ayotte et al 2009;Calatayud et al 2003;Toubin et al 2003). Figure 1.…”