@article{69d856d4d3d84a27b1728bc4e51b757d,
title = "Hydroxide diffuses slower than hydronium in water because its solvated structure inhibits correlated proton transfer",
abstract = "Proton transfer via hydronium and hydroxide ions in water is ubiquitous. It underlies acid-base chemistry, certain enzyme reactions, and even infection by the flu. Despite two centuries of investigation, the mechanism underlying why hydroxide diffuses slower than hydronium in water is still not well understood. Herein, we employ state-of-the-art density-functional-theory-based molecular dynamics - with corrections for non-local van der Waals interactions, and self-interaction in the electronic ground state - to model water and hydrated water ions. At this level of theory, we show that structural diffusion of hydronium preserves the previously recognized concerted behaviour. However, by contrast, proton transfer via hydroxide is less temporally correlated, due to a stabilized hypercoordination solvation structure that discourages proton transfer. Specifically, the latter exhibits non-planar geometry, which agrees with neutron-scattering results. Asymmetry in the temporal correlation of proton transfer leads to hydroxide diffusing slower than hydronium.",
author = "Mohan Chen and Lixin Zheng and Biswajit Santra and Ko, {Hsin Yu} and Distasio, {Robert A.} and Klein, {Michael L.} and Roberto Car and Xifan Wu",
note = "Funding Information: This project was supported by US Department of Energy SciDAC under grant numbers DE-SC0008726 and DE-SC0008626 and partially supported by the Division of Materials Research (DMR) under Award DMR-1552287. R.A.D. acknowledges partial support from Cornell University through start-up funding and the Cornell Center for Materials Research (CCMR) with funding from the National Science Foundation (NSF) MRSEC programme (DMR-1719875). This research used resources of the Argonne Leadership Computing Facility at Argonne National Laboratory, which is supported by the Office of Science of the US Department of Energy under contract number DE-AC02-06CH11357. This research also used resources of the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the US Department of Energy under contract number DE-AC02-05CH11231. X.W. is grateful for the useful discussions with D. Vanderbilt at Rutgers University and A. J. Shanahan at University Medical Center of Princeton. Publisher Copyright: {\textcopyright} 2018 The Author(s).",
year = "2018",
month = apr,
day = "1",
doi = "10.1038/s41557-018-0010-2",
language = "English (US)",
volume = "10",
pages = "413--419",
journal = "Nature Chemistry",
issn = "1755-4330",
publisher = "Nature Publishing Group",
number = "4",
}