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Ab Initio Molecular Dynamics Simulation of a Water–Hydrogen Fluoride Equimolar Mixture
Author(s) -
Simon Christian,
Klein Michael L.
Publication year - 2005
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.200400284
Subject(s) - molecular dynamics , fluoride , hydrogen fluoride , ab initio , hydrogen bond , computational chemistry , ab initio quantum chemistry methods , chemistry , hydrogen , chemical physics , materials science , molecule , inorganic chemistry , organic chemistry
Hydrogen fluoride and water can be mixed in any proportion. The resulting solutions have unique acidic properties. In particular, hydrogen fluoride undergoes a weak‐to‐strong acidity transition with increasing concentration of HF. To supplement the knowledge already obtained on dilute or moderately concentrated solutions and gas‐phase aggregates, an equimolar mixture is studied here by Car–Parrinello molecular dynamics. The natures of the ions and of the complexes formed in the equimolar liquid were determined. Specifically, H 3 O + , H 5 O 2 + , FHOH 2 , and HF 2 − were spontaneously obtained while only hydronium and fluoride ions pre‐exist in the equimolar crystal. The behaviour of the proton in the equimolar liquid was compared with mixtures of other proportions simulated previously in an attempt to relate proton dynamics to acidity. In the same way, the behaviour of HF 2 − was also examined. In this case, proton localization and transfer appeared to be driven by the fluctuating environment of the solvated ion.