Title:
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Dynamical aspects of intermolecular proton transfer in liquid water and low-density amorphous ices
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Author:
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Tahat, Amani; Martí Rabassa, Jordi
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Other authors:
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Universitat Politècnica de Catalunya. Departament de Física i Enginyeria Nuclear; Universitat Politècnica de Catalunya. SIMCON - Grup de Recerca de Simulació per Ordinador en Matèria Condensada |
Abstract:
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The microscopic dynamics of an excess proton in water and in low-density amorphous ices has been studied by means of a series of molecular dynamics simulations. Interaction of water with the proton species was modelled using a multistate empirical valence bond Hamiltonian model. The analysis of the effects of low temperatures on proton diffusion and transfer rates has been considered for a temperature range between 100 and 298 K at the constant density of 1 g cm -3 . We observed a marked slowdown of proton transfer rates at low temperatures, but some episodes are still seen at 100 K. In a similar fashion, mobility of the lone proton gets significantly reduced when temperature decreases below 273 K. The proton transfer in low-density amorphous ice is an activated process with energy barriers between 1–10 kJ/mol depending of the temperature range considered and eventually showing Arrhenius-like behavior. Spectroscopic data indicated the survival of both Zundel and Eigen structures along the whole temperature range, revealed by significant spectral frequency shifts. |
Subject(s):
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-Àrees temàtiques de la UPC::Física -Molecular dynamics -Proton transfer reactions -microscopic dynamics -excess proton in water -low-density amorphous ices -proton transfer -Dinàmica molecular -Protons -- Reaccions de transferència |
Rights:
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Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/ |
Document type:
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Article - Published version Article |
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