Note that elemental potentials taken from alloy descriptions may not work well for the pure species. This is particularly true if the elements were fit for compounds instead of being optimized separately. As with all interatomic potentials, please check to make sure that the performance is adequate for your problem.
AgTaO3, C-H-O, Ce-O, UO2, mox, Ti-O
Silver Tantalate (AgTaO3)H. Gao, A. Otero-de-la-Roza, S.M. Aouadi, E.R. Johnson, and A. Martini, "An empirical model for silver tantalate." Modelling Simul. Mater. Sci. Eng. 21, 055002 (2013). DOI: 10.1088/0965-0393/21/5/055002
Notes: These files were sent by Dr. Ashlie Martini (Univ. California Merced) and approved for distribution on 6 Jul. 2013. The file AgTaO3_40atoms.dat contains atomic coordinates for the 40-atom cell described in the paper. A sample LAMMPS input script to calculate the cohesive energy of that configuration is in in.AgTaO3. This potential was tested on the following versions of LAMMPS: 5Mar12, 12Apr12, 19May12, 4Jul12, 28Oct12, 21Feb13, 5Jun13, 13Jun13, 17Jun13.
Format: MEAM parameters
New! Computed Properties: 2013--Gao-H--AgTaO3
Carbon-Hydrogen-Oxygen (C-H-O) SystemsK. Chenoweth, A.C.T. van Duin and W.A. Goddard, "A ReaxFF Reactive Force Field for Molecular Dynamics Simulations of Hydrocarbon Oxidation," J. Phys. Chem. A 112, 1040-1053, (2008). DOI: 10.1021/jp709896w
Notes: The file "ffield.reax.CHO_2008" was provided by Adri van Duin. From Prof. van Duin: "The ffield-file contains the force field parameters; this file is readable by LAMMPS." The ReaxFF manual (including file formatting information) was obtained from http://www.wag.caltech.edu/home/duin/manual.html. All files were posted with Prof. van Duin's approval. The standalone ReaxFF program is available without charge for academic users by emailing him.
Ceria-Oxygen (Ce-O) SystemBroqvist, P., J. Kullgren, M. J. Wolf, A. C. T. van Duin, and K. Hermansson (2015), ReaxFF Force-Field for Ceria Bulk, Surfaces, and Nanoparticles, The Journal of Physical Chemistry C, 119(24), 13598-13609. DOI: 10.1021/acs.jpcc.5b01597
Notes: This file was sent by J. Kullgren (Uppsala University) on 19 December 2016 and posted with his permission.
J. Kullgren included the following notes:
The parameters have been tested for static calculations of CeO2 and partially reduced CeO(2-x) using the LAMMPS code with the fortran implementation of reaxFF. For energy comparisons, use the in-cell approach (see the paper) when calculating reaction energies.
Note to the users:
After publication we have made further use of the published ceria parameters and noticed an additional (false) local minimum occurring for partially reduced ceria at a short Ce-O distance (approx. 1.89 Angstrom). This may (for example) have consequences for dynamic simulations at moderate temperatures. Our attempts to heal this deficiency have so far destroyed the good performance regarding the ordering of the surface vacancy energies on the (111) surface. In relevant cases, we advice our users to analyse the bond distances from the simulations.
Uranium Dioxide (UO2)Alexander E. Thompson, Bryce Meredig, Marius Stan, C. Wolverton, "Interatomic potential for accurate phonons and defects in UO2," Journal of Nuclear Materials 446, 155-162 (2014). DOI: 10.1016/j.jnucmat.2013.11.040
Notes: These parameters were sent by Dr. Alexander Thompson and posted with his approval on 25 Nov. 2014.
O core 1.772816
O shell -3.737358
U core -2.069827
U shell 5.998911
U shell O shell 1062.316 0.398196 0.0 0.0 15.0
U shell U shell 183.6 0.420031 0.0 0.0 15.0
O shell O shell 10402.58 0.238539 81.75059 0.0 1.150671 2.22 2.460169 15.0
P. Tiwary, A. van de Walle, and N. Gronbech-Jensen, "Ab initio construction of interatomic potentials for uranium dioxide across all interatomic distances," Phys. Rev. B 80, 174302 (2009). DOI: 10.1103/PhysRevB.80.174302
Notes: 31 Jan. 2012 Update: These files have been superceded by the (U,Pu,Np)O2 interatomic potential.
Archival note: For reference, the original files are located in gulp_uo2.lib and README.TXT. They were supplied by Pratyush Tiwary and Axel van de Walle (California Institute of Technology) and posted with their approval on 22 June 2011.
(U,Pu,Np)O2P. Tiwary, A. van de Walle, B. Jeon, and N. Gronbech-Jensen, "Interatomic potentials for mixed oxide and advanced nuclear fuels," Phys. Rev. B 83, 094104 (2011). DOI: 10.1103/PhysRevB.83.094104; P. Tiwary, A. van de Walle, and N. Gronbech-Jensen, Phys. Rev. B 80, 174302 (2009). DOI: 10.1103/PhysRevB.80.174302
Notes: 30 Jan. 2012 Update: These files (version 2.0) were provided by Pratyush Tiwary (California Institute of Technology) and posted with his permission. According to him, this version corrects the 'U-U interaction term (truncated at 4 Angstroms) to resolve problems with thermal expansion in UO2.' Additional information is located in readme_v2.txt
These files replace the original files posted on 17 June 2011 with the approval of Pratyush Tiwary and Axel van de Walle (California Institute of Technology). For reference, the original files are gulp_mox.pdf, gulp_mox.doc, and README.TXT.
Titanium-Oxygen (Ti-O) SystemsZhang, P. and Trinkle, D. R. (2016). A modified embedded atom method potential for interstitial oxygen in titanium. Computational Materials Science, 124, 204-210. DOI: 10.1016/j.commatsci.2016.07.039
Abstract: Modeling oxygen interstitials in titanium requires a new empirical potential. We optimize potential parameters using a fitting database of first-principle oxygen interstitial energies and forces. A new database optimization algorithm based on Bayesian sampling is applied to obtain an optimal potential for a specific testing set of density functional data. A parallel genetic algorithm minimizes the sum of logistic function evaluations of the testing set predictions. We test the transferability of the potential model against oxygen interstitials in HCP titanium, transition barriers between oxygen interstitial sites, and oxygen in the titanium prismatic stacking fault. The potential predicts that the interaction between oxygen and a screw dislocation core is weak and short-ranged.
Notes: This file was sent by Prof. Dallas Trinkle (Univ. of Illinois) on 9 Aug. 2016 and posted with his permission. This version corrects an issue by removing an extra comment line that was not compatible with the LAMMPS MEAM/spline code (original file available here). The reference information was also updated at the same time. Prof. Trinkle said that this potential is specifically intended for dilute oxygen in titanium as there's no oxygen-oxygen interaction.
Date created: October 5, 2010 | Last updated: August 23, 2017