Simulation of Molecular Dynamics of proton impacts on water ice clusters

Ohgaito, Rumi; Hirata, K; Mukai, T.

doi:10.1016/s0273-1177(99)00190-8

Cited by 2 publications

(4 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We cannot perform a quantitative comparison of our results with the previous CT calculations of ref on collision induced water desorption from amorphous ice clusters, because very few (up to 5 per E i ) trajectories were computed in that work. At low values of E i (as low as 0.000 84 eV), these calculations showed that more than one water molecule per trajectory desorbed from a water cluster.…”

Section: Resultsmentioning

confidence: 89%

“…In all CID trajectories, a single water molecule per trajectory is found to desorb and leave the surface, in agreement with the results of previous experiments on H + sticking to ice at high energies (MeV) and calculations on O + sticking to ice at hyperthermal energies (23−115 eV) (see also ref and references therein). Exploratory calculations on proton association with small, cold water clusters found higher probabilities for CID and desorption of more molecules per trajectory, presumably because such clusters have more weakly bound water molecules at their surface than crystalline ice. , The desorbed water molecule initially was always a part of the surface top monolayer at the surface−vacuum interface, i.e., a three-coordinated molecule in the top surface monolayer.…”

Section: Discussionmentioning

confidence: 99%

“…It is also relevant to analytical techniques, such as proton channelling, which can be used to investigate surface disorder of ice . As a result of their importance, interactions of protons with water ice have been studied both experimentally − and theoretically, − for a wide range of conditions.…”

Section: Introductionmentioning

confidence: 99%

“…Scattering of protons from ice has also been studied theoretically. A qualitative, classical trajectory (CT) study was performed for protons scattering from an amorphous ice cluster consisting of 100 water molecules, for E i ranging from high (840 eV) to very low (0.84 meV) . Because very few trajectories were run (up to 5 per E i ), the calculations did not allow quantitative conclusions to be drawn.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Protons Colliding with Crystalline Ice: Proton Reflection and Collision Induced Water Desorption at Low Incidence Energies

et al. 2005

View full text Add to dashboard Cite

We present results of classical trajectory (CT) calculations on the sticking of protons to the basal plane (0001) face of crystalline ice, for normal incidence at a surface temperature (Ts) of 80 K. The calculations were performed for moderately low incidence energies (Ei) ranging from 0.05 to 4.0 eV. Surprisingly, significant reflection is predicted at low values of Ei (< or = 0.2 eV) due to repulsive electrostatic interactions between the incident proton and the surface water molecules with one of their H-atoms pointing upward toward the gas phase. The sticking probability increases with Ei and converges to unity for Ei > or = 0.8 eV. In the case of sticking, the proton is trapped in the ice forming a Zundel complex (H5O2+), with an average binding energy of 9.9 eV with a standard deviation of 0.5 eV, independent of the value of Ei. In nearly all sticking trajectories, the proton is implanted into the ice surface, with a penetration depth that increases with Ei. The strong interaction with the neighboring water molecules leads to a local rupture of the hydrogen bonding network, resulting in collision induced desorption of water (puffing), a process that occurs with significant probability even at the lowest Ei considered. The probability of water desorption increases with Ei. In nearly all trajectories in which water desorption occurs, a single three-coordinated water molecule is desorbed from the topmost monolayer.

show abstract

Section: Resultsmentioning

confidence: 89%