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Title: Revisiting the hydration structure of aqueous Na +

Abstract

In this paper, a combination of theory, X-ray diffraction (XRD) and extended x-ray absorption fine structure (EXAFS) are used to probe the hydration structure of aqueous Na +. The high spatial resolution of the XRD measurements corresponds to Qmax = 24 Å –1 while the first-reported Na K-edge EXAFS measurements have a spatial resolution corresponding to 2k = Qmax = 16 Å –1. Both provide an accurate measure of the shape and position of the first peak in the Na–O pair distribution function, g NaO(r). The measured Na–O distances of 2.384 ± 0.003 Å (XRD) and 2.37 ± 0.024 Å (EXAFS) are in excellent agreement. These measurements show a much shorter Na–O distance than generally reported in the experimental literature (Na–O avg ~ 2.44 Å) although the current measurements are in agreement with recent neutron diffraction measurements. The measured Na–O coordination number from XRD is 5.5 ± 0.3. The measured structure is compared with both classical and first-principles density functional theory (DFT) simulations. Both of the DFT-based methods, revPBE and BLYP, predict a Na–O distance that is too long by about 0.05 Å with respect to the experimental data (EXAFS and XRD). The inclusion of dispersion interactions (–D3 and –D2)more » significantly worsens the agreement with experiment by further increasing the Na–O distance by 0.07 Å. In contrast, the use of a classical Na–O Lennard-Jones potential with SPC/E water accurately predicts the Na–O distance as 2.39 Å although the Na–O peak is over-structured with respect to experiment.« less

Authors:
 [1];  [1]; ORCiD logo [2];  [1];  [3];  [1];  [2]; ORCiD logo [1];  [1]
  1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
  2. Argonne National Lab. (ANL), Argonne, IL (United States)
  3. Paul Scherrer Inst. (PSI), Villigen (Switzerland)
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1389653
Alternate Identifier(s):
OSTI ID: 1349340
Grant/Contract Number:  
AC02-06CH11357; AC05-76RL1830; FG02-09ER46650
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 146; Journal Issue: 8; Journal ID: ISSN 0021-9606
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Galib, M., Baer, M. D., Skinner, L. B., Mundy, C. J., Huthwelker, T., Schenter, G. K., Benmore, C. J., Govind, N., and Fulton, John L. Revisiting the hydration structure of aqueous Na+. United States: N. p., 2017. Web. doi:10.1063/1.4975608.
Galib, M., Baer, M. D., Skinner, L. B., Mundy, C. J., Huthwelker, T., Schenter, G. K., Benmore, C. J., Govind, N., & Fulton, John L. Revisiting the hydration structure of aqueous Na+. United States. doi:10.1063/1.4975608.
Galib, M., Baer, M. D., Skinner, L. B., Mundy, C. J., Huthwelker, T., Schenter, G. K., Benmore, C. J., Govind, N., and Fulton, John L. Mon . "Revisiting the hydration structure of aqueous Na+". United States. doi:10.1063/1.4975608. https://www.osti.gov/servlets/purl/1389653.
@article{osti_1389653,
title = {Revisiting the hydration structure of aqueous Na+},
author = {Galib, M. and Baer, M. D. and Skinner, L. B. and Mundy, C. J. and Huthwelker, T. and Schenter, G. K. and Benmore, C. J. and Govind, N. and Fulton, John L.},
abstractNote = {In this paper, a combination of theory, X-ray diffraction (XRD) and extended x-ray absorption fine structure (EXAFS) are used to probe the hydration structure of aqueous Na+. The high spatial resolution of the XRD measurements corresponds to Qmax = 24 Å–1 while the first-reported Na K-edge EXAFS measurements have a spatial resolution corresponding to 2k = Qmax = 16 Å–1. Both provide an accurate measure of the shape and position of the first peak in the Na–O pair distribution function, gNaO(r). The measured Na–O distances of 2.384 ± 0.003 Å (XRD) and 2.37 ± 0.024 Å (EXAFS) are in excellent agreement. These measurements show a much shorter Na–O distance than generally reported in the experimental literature (Na–Oavg ~ 2.44 Å) although the current measurements are in agreement with recent neutron diffraction measurements. The measured Na–O coordination number from XRD is 5.5 ± 0.3. The measured structure is compared with both classical and first-principles density functional theory (DFT) simulations. Both of the DFT-based methods, revPBE and BLYP, predict a Na–O distance that is too long by about 0.05 Å with respect to the experimental data (EXAFS and XRD). The inclusion of dispersion interactions (–D3 and –D2) significantly worsens the agreement with experiment by further increasing the Na–O distance by 0.07 Å. In contrast, the use of a classical Na–O Lennard-Jones potential with SPC/E water accurately predicts the Na–O distance as 2.39 Å although the Na–O peak is over-structured with respect to experiment.},
doi = {10.1063/1.4975608},
journal = {Journal of Chemical Physics},
number = 8,
volume = 146,
place = {United States},
year = {Mon Feb 27 00:00:00 EST 2017},
month = {Mon Feb 27 00:00:00 EST 2017}
}

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Works referenced in this record:

Generalized Gradient Approximation Made Simple
journal, October 1996

  • Perdew, John P.; Burke, Kieron; Ernzerhof, Matthias
  • Physical Review Letters, Vol. 77, Issue 18, p. 3865-3868
  • DOI: 10.1103/PhysRevLett.77.3865

NWChem: A comprehensive and scalable open-source solution for large scale molecular simulations
journal, September 2010

  • Valiev, M.; Bylaska, E. J.; Govind, N.
  • Computer Physics Communications, Vol. 181, Issue 9, p. 1477-1489
  • DOI: 10.1016/j.cpc.2010.04.018

Semiempirical GGA-type density functional constructed with a long-range dispersion correction
journal, January 2006

  • Grimme, Stefan
  • Journal of Computational Chemistry, Vol. 27, Issue 15, p. 1787-1799
  • DOI: 10.1002/jcc.20495