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Title: Topological ordering in liquid UO 2

Abstract

A molecular dynamics model of liquid UO2 that is in good agreement with recent high-energy x-ray diffraction data has been analyzed using the Bhatia–Thornton formalism. A pre-peak appears in the topological structure factor S NN(Q) at Q = 1.85(1)Å-1 which is not present in the more common, element specific Faber–Ziman partial structure factors. A radical Voronoi tessellation of the 3D molecular dynamics model shows the presence of a wide distribution of clusters, consistent with presence of highly mobile oxygen atoms. However, 4-fold Voronoi polyhedra (n 4) are found to dominate the structure and the majority of clusters can be described by the distribution n 3 ≤ n 4 ≥ n 5. It is argued that an open network of 4-fold Voronoi polyhedra could explain the origin of the pre-peak in S NN(Q) and the topological ordering observed in liquid UO2.

Authors:
 [1];  [2];  [1];  [3];  [4];  [1]
  1. Argonne National Lab. (ANL), Argonne, IL (United States)
  2. Argonne National Lab. (ANL), Argonne, IL (United States); Stony Brook Univ., NY (United States)
  3. Materials Development, Inc., Arlington Heights, IL (United States)
  4. Stony Brook Univ., NY (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
OSTI Identifier:
1248943
DOE Contract Number:  
AC02-06CH11357
Resource Type:
Journal Article
Journal Name:
Journal of Physics. Condensed Matter
Additional Journal Information:
Journal Volume: 28; Journal Issue: 1; Journal ID: ISSN 0953-8984
Publisher:
IOP Publishing
Country of Publication:
United States
Language:
English
Subject:
22 GENERAL STUDIES OF NUCLEAR REACTORS

Citation Formats

Benmore, C. J., Skinner, L. B., Lee, B., Weber, J. K. R., Parise, J. B., and Williamson, M. Topological ordering in liquid UO 2. United States: N. p., 2015. Web. doi:10.1088/0953-8984/28/1/015102.
Benmore, C. J., Skinner, L. B., Lee, B., Weber, J. K. R., Parise, J. B., & Williamson, M. Topological ordering in liquid UO 2. United States. https://doi.org/10.1088/0953-8984/28/1/015102
Benmore, C. J., Skinner, L. B., Lee, B., Weber, J. K. R., Parise, J. B., and Williamson, M. 2015. "Topological ordering in liquid UO 2". United States. https://doi.org/10.1088/0953-8984/28/1/015102.
@article{osti_1248943,
title = {Topological ordering in liquid UO 2},
author = {Benmore, C. J. and Skinner, L. B. and Lee, B. and Weber, J. K. R. and Parise, J. B. and Williamson, M.},
abstractNote = {A molecular dynamics model of liquid UO2 that is in good agreement with recent high-energy x-ray diffraction data has been analyzed using the Bhatia–Thornton formalism. A pre-peak appears in the topological structure factor S NN(Q) at Q = 1.85(1)Å-1 which is not present in the more common, element specific Faber–Ziman partial structure factors. A radical Voronoi tessellation of the 3D molecular dynamics model shows the presence of a wide distribution of clusters, consistent with presence of highly mobile oxygen atoms. However, 4-fold Voronoi polyhedra (n 4) are found to dominate the structure and the majority of clusters can be described by the distribution n 3 ≤ n 4 ≥ n 5. It is argued that an open network of 4-fold Voronoi polyhedra could explain the origin of the pre-peak in S NN(Q) and the topological ordering observed in liquid UO2.},
doi = {10.1088/0953-8984/28/1/015102},
url = {https://www.osti.gov/biblio/1248943}, journal = {Journal of Physics. Condensed Matter},
issn = {0953-8984},
number = 1,
volume = 28,
place = {United States},
year = {Thu Dec 10 00:00:00 EST 2015},
month = {Thu Dec 10 00:00:00 EST 2015}
}