× Updated! Potentials that share interactions are now listed as related models.
 
Citation: R.S. Elliott, and A. Akerson (2015), "Efficient "universal" shifted Lennard-Jones model for all KIM API supported species".

Notes: This is the Co interaction from the "Universal" parameterization for the openKIM LennardJones612 model driver.The parameterization uses a shifted cutoff so that all interactions have a continuous energy function at the cutoff radius. This model was automatically fit using Lorentz-Berthelotmixing rules. It reproduces the dimer equilibrium separation (covalent radii) and the bond dissociation energies. It has not been fitted to other physical properties and its ability to model structures other than dimers is unknown. See the README and params files on the KIM model page for more details.

See Computed Properties
Notes: Listing found at https://openkim.org.
Link(s):
Citation: W.-P. Dong, H.-K. Kim, W.-S. Ko, B.-M. Lee, and B.-J. Lee (2012), "Atomistic modeling of pure Co and Co–Al system", Calphad, 38, 7-16. DOI: 10.1016/j.calphad.2012.04.001.
Abstract: Interatomic potentials for pure Co and the Co–Al binary system have been developed based on the second nearest-neighbor modified embedded-atom method (2NN MEAM) potential formalism. The potentials can describe various fundamental physical properties of the relevant materials in good agreement with experimental information. The potential is utilized to an atomistic computation of interfacial properties between fcc-Co (γ) and Co3Al (γ′) phases. It is found that the anisotropy in the γ/γ′ interfacial energy is relatively small and leaves a room for further modification by alloying other elements. The applicability of the atomistic approach to an elaborate alloy design of advanced Co-based superalloys through the investigation of the effect of alloying elements on interfacial and elastic properties is discussed.

LAMMPS pair_style meam (2012--Dong-W-P--Co--LAMMPS--ipr1)
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Notes: These files are based on files obtained from http://cmse.postech.ac.kr/home_2nnmeam.
File(s):
See Computed Properties
Notes: Listing found at https://openkim.org.
Link(s):
Citation: G.P. Purja Pun, and Y. Mishin (2012), "Embedded-atom potential for hcp and fcc cobalt", Physical Review B, 86(13), 134116. DOI: 10.1103/physrevb.86.134116.
Abstract: We report on the development of an embedded-atom interatomic potential representing basic properties of both the hcp and the fcc phases of cobalt with nearly equal accuracy. The potential also reproduces the structural phase transformation between the two phases at a temperature close to the experimental value. The proposed potential can be used for large-scale atomistic simulations of cobalt microstructures over a wide range of temperatures. In a more general context, it offers a model for studying thermodynamic and kinetic properties of hcp/fcc interfaces and microstructure evolution in two-phase materials.

LAMMPS pair_style eam/alloy (2012--Purja-Pun-G-P--Co--LAMMPS--ipr1)
See Computed Properties
Notes: This interatomic potential file was generated by G.P. Purja Pun (George Mason Univ.) and sent by Y. Mishin on 19 Oct. 2012. It was posted with their permission on 22 Oct. 2012. 29 Oct. 2012: The reference was updated when the manuscript was published. Testing information is available in Co_PurjaPun_2012_potential_test.pdf. This file was provided by Y. Mishin and G.P. Purja Pun.
File(s):
See Computed Properties
Notes: Listing found at https://openkim.org. This KIM potential is based on the files from 2012--Purja-Pun-G-P--Co--LAMMPS--ipr1.
Link(s):
Citation: X.W. Zhou, R.A. Johnson, and H.N.G. Wadley (2004), "Misfit-energy-increasing dislocations in vapor-deposited CoFe/NiFe multilayers", Physical Review B, 69(14), 144113. DOI: 10.1103/physrevb.69.144113.
Abstract: Recent molecular dynamics simulations of the growth of [Ni0.8Fe0.2/Au] multilayers have revealed the formation of misfit-strain-reducing dislocation structures very similar to those observed experimentally. Here we report similar simulations showing the formation of edge dislocations near the interfaces of vapor-deposited (111) [NiFe/CoFe/Cu] multilayers. Unlike misfit dislocations that accommodate lattice mismatch, the dislocation structures observed here increase the mismatch strain energy. Stop-action observations of the dynamically evolving atomic structures indicate that during deposition on the (111) surface of a fcc lattice, adatoms may occupy either fcc sites or hcp sites. This results in the random formation of fcc and hcp domains, with dislocations at the domain boundaries. These dislocations enable atoms to undergo a shift from fcc to hcp sites, or vice versa. These shifts lead to missing atoms, and therefore a later deposited layer can have missing planes compared to a previously deposited layer. This dislocation formation mechanism can create tensile stress in fcc films. The probability that such dislocations are formed was found to quickly diminish under energetic deposition conditions.

FORTRAN (2004--Zhou-X-W--Co--FORTRAN--ipr1)
Notes: These are the original files sent by X.W. Zhou (Sandia National Laboratory) and posted with his permission. C.A. Becker (NIST) modified create.f to include the reference in the generated potential files and the EAM.input file for this composition. These files can be used to generate alloy potentials for Cu, Ag, Au, Ni, Pd, Pt, Al, Pb, Fe, Mo, Ta, W, Mg, Co, Ti, and Zr by editing EAM.input. However, as addressed in the reference, these potentials were not designed for use with metal compounds.
File(s): superseded


LAMMPS pair_style eam/alloy (2004--Zhou-X-W--Co--LAMMPS--ipr1)
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Notes: This file was generated by C.A. Becker (NIST) from create.f and posted with X.W. Zhou's (Sandia National Laboratory) permission.
File(s): superseded


FORTRAN (2004--Zhou-X-W--Co--FORTRAN--ipr2)
Notes: The file Zhou04_create_v2.f is an updated version of create.f modified by L.M. Hale (NIST) following advice from X.W. Zhou (Sandia National Laboratory). This version removes spurious fluctuations in the tabulated functions of the original potential files caused by single/double precision floating point number conflicts.
File(s):
LAMMPS pair_style eam/alloy (2004--Zhou-X-W--Co--LAMMPS--ipr2)
See Computed Properties
Notes: This file was generated by L.M. Hale from Zhou04_create_v2.f on 13 April 2018 and posted with X.W. Zhou's (Sandia National Laboratory) permission. This version corrects an issue with spurious fluctuations in the tabulated functions.
File(s):
See Computed Properties
Notes: Listing found at https://openkim.org. This KIM potential is based on the files from 2004--Zhou-X-W--Co--LAMMPS--ipr1.
Link(s):
See Computed Properties
Notes: Listing found at https://openkim.org. This KIM potential is based on the files from 2004--Zhou-X-W--Co--LAMMPS--ipr2.
Link(s):
 
Citation: G.P. Purja Pun, V. Yamakov, and Y. Mishin (2015), "Interatomic potential for the ternary Ni–Al–Co system and application to atomistic modeling of the B2–L10 martensitic transformation", Modelling and Simulation in Materials Science and Engineering, 23(6), 065006. DOI: 10.1088/0965-0393/23/6/065006.
Abstract: Ni–Al–Co is a promising system for ferromagnetic shape memory applications. This paper reports on the development of a ternary embedded-atom potential for this system by fitting to experimental and first-principles data. Reasonably good agreement is achieved for physical properties between values predicted by the potential and values known from experiment and/or first-principles calculations. The potential reproduces basic features of the martensitic phase transformation from the B2-ordered high-temperature phase to a tetragonal CuAu-ordered low-temperature phase. The compositional and temperature ranges of this transformation and the martensite microstructure predicted by the potential compare well with existing experimental data. These results indicate that the proposed potential can be used for simulations of the shape memory effect in the Ni–Al–Co system.

Notes: The reference information was updated on 26 Aug. 2015.

LAMMPS pair_style eam/alloy (2015--Purja-Pun-G-P--Al-Co--LAMMPS--ipr1)
See Computed Properties
Notes: This file was sent by Y. Mishin (George Mason Univ.) on 17 Sept. 2013 and was posted on 17 Jan. 2014. This version is compatible with LAMMPS. Validation and usage information can be found in Mishin-Al-Co-2013_lammps.pdf.
File(s): superseded


LAMMPS pair_style eam/alloy (2015--Purja-Pun-G-P--Al-Co--LAMMPS--ipr2)
See Computed Properties
Notes: This file was sent by G Purja Pun (George Mason Univ.) on 12 Oct. 2015 and was posted on 15 Dec. 2015. This version corrects an issue with the cutoff distance for Co interactions that was discovered during calculations of pressure dependent elastic constants.
File(s):
See Computed Properties
Notes: Listing found at https://openkim.org. This KIM potential is based on the files from 2015--Purja-Pun-G-P--Al-Co--LAMMPS--ipr2.
Link(s):
Citation: W.-P. Dong, H.-K. Kim, W.-S. Ko, B.-M. Lee, and B.-J. Lee (2012), "Atomistic modeling of pure Co and Co–Al system", Calphad, 38, 7-16. DOI: 10.1016/j.calphad.2012.04.001.
Abstract: Interatomic potentials for pure Co and the Co–Al binary system have been developed based on the second nearest-neighbor modified embedded-atom method (2NN MEAM) potential formalism. The potentials can describe various fundamental physical properties of the relevant materials in good agreement with experimental information. The potential is utilized to an atomistic computation of interfacial properties between fcc-Co (γ) and Co3Al (γ′) phases. It is found that the anisotropy in the γ/γ′ interfacial energy is relatively small and leaves a room for further modification by alloying other elements. The applicability of the atomistic approach to an elaborate alloy design of advanced Co-based superalloys through the investigation of the effect of alloying elements on interfacial and elastic properties is discussed.

See Computed Properties
Notes: These potential files were obtained from http://cmse.postech.ac.kr/home_2nnmeam, accessed Nov 9, 2020.
File(s):
See Computed Properties
Notes: Listing found at https://openkim.org.
Link(s):
Citation: C. Vailhé, and D. Farkas (1997), "Shear faults and dislocation core structures in B2 CoAl", Journal of Materials Research, 12(10), 2559-2570. DOI: 10.1557/jmr.1997.0340.
Abstract: Interatomic potentials of the embedded atom and embedded defect type were derived for the Co–Al system by empirical fitting to the properties of the B2 CoAl phase. The embedded atom potentials reproduced most of the properties needed, except that, in using this method, the elastic constants cannot be fitted exactly because CoAl has a negative Cauchy pressure. In order to overcome this limitation and fit the elastic constants correctly, angular forces were added using the embedded defect technique. The effects of angular forces to the embedded atom potentials were seen in the elastic constants, particularly C44. Planar fault energies changed up to 30% in the 110 and 112 γ surfaces and the vacancy formation energies were also very sensitive to the non-central forces. Dislocation core structures and Peierls stress values were computed for the 〈100〉 and 〈111〉 dislocations without angular forces. As a general result, the dislocations with a planar core moved for critical stress values below 250 MPa in contrast with the nonplanar cores for which the critical stress values were above 1500 MPa. The easiest dislocations to move were the 1/2〈111〉 edge superpartials, and the overall preferred slip plane was 110. These results were compared with experimental observations in CoAl and previously simulated dislocations in NiAl.

See Computed Properties
Notes: Listing found at https://openkim.org.
Link(s):
 
Citation: D. Farkas, and A. Caro (2020), "Model interatomic potentials for Fe–Ni–Cr–Co–Al high-entropy alloys", Journal of Materials Research, 35, 3031-3040. DOI: 10.1557/jmr.2020.294.
Abstract: A set of embedded atom model (EAM) interatomic potentials was developed to represent highly idealized face-centered cubic (FCC) mixtures of Fe–Ni–Cr–Co–Al at near-equiatomic compositions. Potential functions for the transition metals and their crossed interactions are taken from our previous work for Fe–Ni–Cr–Co–Cu [D. Farkas and A. Caro: J. Mater. Res. 33 (19), 3218–3225, 2018], while cross-pair interactions involving Al were developed using a mix of the component pair functions fitted to known intermetallic properties. The resulting heats of mixing of all binary equiatomic random FCC mixtures not containing Al is low, but significant short-range ordering appears in those containing Al, driven by a large atomic size difference. The potentials are utilized to predict the relative stability of FCC quinary mixtures, as well as ordered L12 and B2 phases as a function of Al content. These predictions are in qualitative agreement with experiments. This interatomic potential set is developed to resemble but not model precisely the properties of this complex system, aiming at providing a tool to explore the consequences of the addition of a large size-misfit component into a high entropy mixture that develops multiphase microstructures.

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Notes: This file was sent by Diana Farkas (Virginia Tech) on 27 Oct. 2020 and posted with her permission.
File(s):
 
Citation: Y.-K. Kim, W.-S. Jung, and B.-J. Lee (2015), "Modified embedded-atom method interatomic potentials for the Ni-Co binary and the Ni-Al-Co ternary systems", Modelling and Simulation in Materials Science and Engineering, 23(5), 055004. DOI: 10.1088/0965-0393/23/5/055004.
Abstract: Interatomic potentials for the Ni-Co binary and Ni-Al-Co ternary systems have been developed on the basis of the second nearest-neighbor modified embedded-atom method (2NN MEAM) formalism. The potentials describe structural, thermodynamic, deformation and defect properties of solid solution phases or compound phases in reasonable agreements with experiments or first-principles calculations. The results demonstrate the transferability of the potentials and their applicability to large-scale atomistic simulations to investigate the effect of an alloying element, cobalt, on various microstructural factors related to mechanical properties of Ni-based superalloys on an atomic scale.

See Computed Properties
Notes: These potential files were obtained from http://cmse.postech.ac.kr/home_2nnmeam, accessed Nov 9, 2020.
File(s):
Citation: G.P. Purja Pun, V. Yamakov, and Y. Mishin (2015), "Interatomic potential for the ternary Ni–Al–Co system and application to atomistic modeling of the B2–L10 martensitic transformation", Modelling and Simulation in Materials Science and Engineering, 23(6), 065006. DOI: 10.1088/0965-0393/23/6/065006.
Abstract: Ni–Al–Co is a promising system for ferromagnetic shape memory applications. This paper reports on the development of a ternary embedded-atom potential for this system by fitting to experimental and first-principles data. Reasonably good agreement is achieved for physical properties between values predicted by the potential and values known from experiment and/or first-principles calculations. The potential reproduces basic features of the martensitic phase transformation from the B2-ordered high-temperature phase to a tetragonal CuAu-ordered low-temperature phase. The compositional and temperature ranges of this transformation and the martensite microstructure predicted by the potential compare well with existing experimental data. These results indicate that the proposed potential can be used for simulations of the shape memory effect in the Ni–Al–Co system.

Notes: The reference information was updated on 26 Aug. 2015.

See Computed Properties
Notes: This file was sent by Y. Mishin (George Mason Univ.) on 17 Sept. 2013 and was posted on 17 Jan. 2014. This version is compatible with LAMMPS. Validation and usage information can be found in Mishin-Ni-Al-Co-2013_lammps.pdf.
File(s): superseded


See Computed Properties
Notes: This file was sent by G Purja Pun (George Mason Univ.) on 12 Oct. 2015 and was posted on 15 Dec. 2015. This version corrects an issue with the cutoff distance for Co interactions that was discovered during calculations of pressure dependent elastic constants.
File(s):
See Computed Properties
Notes: Listing found at https://openkim.org. This KIM potential is based on the files from 2015--Purja-Pun-G-P--Ni-Al-Co--LAMMPS--ipr2.
Link(s):
Citation: P. Brommer, and F. Gähler (2006), "Effective potentials for quasicrystals fromab-initiodata", Philosophical Magazine, 86(6-8), 753-758. DOI: 10.1080/14786430500333349.
Abstract: Classical effective potentials are indispensable for any large-scale atomistic simulations, and the relevance of simulation results crucially depends on the quality of the potentials used. For complex alloys such as quasicrystals, however, realistic effective potentials are almost non-existent. We report here our efforts to develop effective potentials especially for quasicrystalline alloy systems. We use the so-called force-matching method, in which the potential parameters are adapted so as to reproduce the forces and energies optimally in a set of suitably chosen reference configurations. These reference data are calculated with ab-initio methods. As a first application, embedded-atom method potentials for decagonal Al–Ni–Co, icosahedral Ca–Cd, and both icosahedral and decagonal Mg–Zn quasicrystals have been constructed. The influence of the potential range and degree of specialization on the accuracy and other properties is discussed and compared.

Notes: This is for the Potential A model described in the reference

See Computed Properties
Notes: Listing found at https://openkim.org.
Link(s):
Citation: P. Brommer, and F. Gähler (2006), "Effective potentials for quasicrystals fromab-initiodata", Philosophical Magazine, 86(6-8), 753-758. DOI: 10.1080/14786430500333349.
Abstract: Classical effective potentials are indispensable for any large-scale atomistic simulations, and the relevance of simulation results crucially depends on the quality of the potentials used. For complex alloys such as quasicrystals, however, realistic effective potentials are almost non-existent. We report here our efforts to develop effective potentials especially for quasicrystalline alloy systems. We use the so-called force-matching method, in which the potential parameters are adapted so as to reproduce the forces and energies optimally in a set of suitably chosen reference configurations. These reference data are calculated with ab-initio methods. As a first application, embedded-atom method potentials for decagonal Al–Ni–Co, icosahedral Ca–Cd, and both icosahedral and decagonal Mg–Zn quasicrystals have been constructed. The influence of the potential range and degree of specialization on the accuracy and other properties is discussed and compared.

Notes: This is for the Potential B model described in the reference

See Computed Properties
Notes: Listing found at https://openkim.org.
Link(s):
 
Citation: W.-M. Choi, Y. Kim, D. Seol, and B.-J. Lee (2017), "Modified embedded-atom method interatomic potentials for the Co-Cr, Co-Fe, Co-Mn, Cr-Mn and Mn-Ni binary systems", Computational Materials Science, 130, 121-129. DOI: 10.1016/j.commatsci.2017.01.002.
Abstract: Interatomic potentials for the Co-Cr, Co-Fe, Co-Mn, Cr-Mn and Mn-Ni binary systems have been developed in the framework of the second nearest-neighbor modified embedded-atom method (2NN MEAM) formalism. The potentials describe various fundamental alloy behaviors (structural, elastic and thermodynamic behavior of solution and compound phases), mostly in reasonable agreements with experimental data or first-principles calculations. The potentials can be utilized to complete the interatomic potential for the CoCrFeMnNi alloy and to investigate the atomic scale physical metallurgy of high entropy alloys.

See Computed Properties
Notes: These potential files were obtained from http://cmse.postech.ac.kr/home_2nnmeam, accessed Nov 9, 2020.
File(s):
 
Citation: O.R. Deluigi, R.C. Pasianot, F.J. Valencia, A. Caro, D. Farkas, and E.M. Bringa (2021), "Simulations of primary damage in a High Entropy Alloy: Probing enhanced radiation resistance", Acta Materialia, 213, 116951. DOI: 10.1016/j.actamat.2021.116951.
Abstract: High Entropy Alloys (HEA) attract attention as possible radiation resistant materials, a feature observed in some experiments that has been attributed to several unique properties of HEA, in particular to the disorder-induced reduced thermal conductivity and to the peculiar defect properties originating from the chemical complexity. To explore the origin of such behavior we study the early stages (less than 0.1 ns), of radiation damage response of a HEA using molecular dynamics simulations of collision cascades induced by primary knock-on atoms (PKA) with 10, 20 and 40 keV, at room temperature, on an idealized model equiatomic quinary fcc FeNiCrCoCu alloy, the corresponding "Average Atom" (AA) material, and on pure Ni. We include accurate corrections to describe short-range atomic interactions during the cascade. In all cases the average number of defects in the HEA is lower than for pure Ni, which has been previously used to help claiming that HEA is radiation resistant. However, simulated defect evolution during primary damage, including the number of surviving Frenkel Pairs, and the defect cluster size distributions are nearly the same in all cases, within our statistical uncertainty. The number of surviving FP in the alloy is predicted fairly well by analytical models of defect production in pure materials. All of this indicates that the origin of radiation resistance in HEAs as observed in experiments may not be related to a reduction in primary damage due to chemical disorder, but is probably caused by longer-time defect evolution.

Notes: This is a modified version of 2018--Farkas-D-Caro-A--Fe-Ni-Cr-Co-Cu that adds the ZBL correction at shorter interatomic distances making it suitable for radiation studies.

See Computed Properties
Notes: This file was provided by Diana Farkas (Virginia Tech) on May 16, 2021 and posted with her permission.
File(s):
Citation: D. Farkas, and A. Caro (2018), "Model interatomic potentials and lattice strain in a high-entropy alloy", Journal of Materials Research, 33(19), 3218-3225. DOI: 10.1557/jmr.2018.245.
Abstract: A set of embedded atom method model interatomic potentials is presented to represent a high-entropy alloy with five components. The set is developed to resemble but not model precisely face-centered cubic (fcc) near-equiatomic mixtures of Fe–Ni–Cr–Co–Cu. The individual components have atomic sizes deviating up to 3%. With the heats of mixing of all binary equiatomic random fcc mixtures being less than 0.7 kJ/mol and the corresponding value for the quinary being −0.0002 kJ/mol, the potentials predict the random equiatomic fcc quinary mixture to be stable with respect to phase separation or ordering and with respect to bcc and hcp random mixtures. The details of lattice distortion, strain, and stress states in this phase are reported. The standard deviation in the individual nearest neighbor bond lengths was found to be in the range of 2%. Most importantly, individual atoms in the alloy were found to be under atomic strains up to 0.5%, corresponding to individual atomic stresses up to several GPa.

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Notes: This file was provided by Diana Farkas (Virginia Tech) on 19 March 2019 and posted with her permission. Update 2019-05-20: Superseded by new version.
File(s): superseded


See Computed Properties
Notes: This file was provided by Diana Farkas (Virginia Tech) on 20 May 2019. Professor Farkas notes "The update is to make the potentials go to zero smoothly for distances of 5.8 Å. The original version went up to 6 Å and the last 0.2 Å were not smooth. This does not affect any of the common calculations but may make a difference in some cases like Peierls stresses of dislocations."
File(s):
 
Citation: R. Gröger, V. Vitek, and A. Dlouhý (2020), "Effective pair potential for random fcc CoCrFeMnNi alloys", Modelling and Simulation in Materials Science and Engineering, 28(7), 075006. DOI: 10.1088/1361-651x/ab7f8b.
Abstract: The single-phase equiatomic CoCrFeMnNi alloy is a random solid solution of five elements on the face-centered cubic lattice, whose pure constituents crystallize in very different structures and exhibit diverse magnetic properties. Due to the randomness of the alloy, 80% of nearest neighbor bonds are between unlike elements and thus the details of bonding in pure structures are less important. The elastic moduli of this alloy give rise to small Cauchy pressure C12 − C44, which suggests that the dominant part of bonding may be described by a simple pair potential. We test this hypothesis by developing a long-range Lennard-Jones potential in which the equilibrium crystal structures of pure constituents are taken as reference. The standard mixing rules for regular solutions are then adopted to obtain parameters for bonds between unlike elements in the quinary system. The transferability of this potential to quaternary CoCrFeNi, ternary CoCrNi, and binary FeNi alloys is investigated and the predictions compared with experiments and density functional theory calculations. By sampling over a large number of random configurations, we investigate the effect of compositional randomness on misfit volumes, energies of point defects and stacking faults, and the dislocation friction stresses experienced by moving edge and screw dislocations.

Notes: R. Gröger notes that "This is the Mie n-2n potential, where n=6 was found to give the best results - it is the same as the Lennard-Jones 6-12 potential. These potential files contain parameterizations of the Co-Cr-Fe-Mn-Ni system intended for studies of compositionally complex alloys with spatially random distributions of individual elements. Although it was developed primarily for studies of the quinary fcc CoCrFeMnNi system, the paper above demonstrates that it can be used equally well for quaternaries and ternaries. We emphasize that the model ceases to be applicable for binary and unary systems, where most or all first neighbor bonds are between the same elements."

See Computed Properties
Notes: These files were provided by Roman Gröger on Oct 23, 2021 and posted with his permission. The file mie.mod shows how to include these potentials in LAMMPS simulations via "include mie.mod".
File(s):
Citation: W.-M. Choi, Y.H. Jo, S.S. Sohn, S. Lee, and B.-J. Lee (2018), "Understanding the physical metallurgy of the CoCrFeMnNi high-entropy alloy: an atomistic simulation study", npj Computational Materials, 4(1), 1. DOI: 10.1038/s41524-017-0060-9.
Abstract: Although high-entropy alloys (HEAs) are attracting interest, the physical metallurgical mechanisms related to their properties have mostly not been clarified, and this limits wider industrial applications, in addition to the high alloy costs. We clarify the physical metallurgical reasons for the materials phenomena (sluggish diffusion and micro-twining at cryogenic temperatures) and investigate the effect of individual elements on solid solution hardening for the equiatomic CoCrFeMnNi HEA based on atomistic simulations (Monte Carlo, molecular dynamics and molecular statics). A significant number of stable vacant lattice sites with high migration energy barriers exists and is thought to cause the sluggish diffusion. We predict that the hexagonal close-packed (hcp) structure is more stable than the face-centered cubic (fcc) structure at 0 K, which we propose as the fundamental reason for the micro-twinning at cryogenic temperatures. The alloying effect on the critical resolved shear stress (CRSS) is well predicted by the atomistic simulation, used for a design of non-equiatomic fcc HEAs with improved strength, and is experimentally verified. This study demonstrates the applicability of the proposed atomistic approach combined with a thermodynamic calculation technique to a computational design of advanced HEAs.

See Computed Properties
Notes: These potential files were obtained from http://cmse.postech.ac.kr/home_2nnmeam, accessed Nov 9, 2020.
File(s):
 
Citation: J. Wang, S.-H. Oh, and B.-J. Lee (2020), "Second-nearest-neighbor modified embedded-atom method interatomic potential for Cu-M (M = Co, Mo) binary systems", Computational Materials Science, 178, 109627. DOI: 10.1016/j.commatsci.2020.109627.
Abstract: Second-nearest-neighbor modified embedded-atom method (2NN MEAM) interatomic potentials for Cu-M (M = Co, Mo) binary systems have been developed. The Cu-M potentials can be extended to Pt-Cu-M ternary 2NN MEAM potentials being combined with already existing Pt-M potentials and can be utilized for atomistic simulations to design inexpensive and efficient platinum alloy catalysts. The potentials reproduce fundamental material properties such as structural and thermodynamic properties of compound and solution phases in reasonable agreement with experimental data. Herein, the validity of the developed potentials for atomistic simulation is ascertained.

LAMMPS pair_style meam (2020--Wang-J--Cu-Co--LAMMPS--ipr1)
See Computed Properties
Notes: These potential files were obtained from http://cmse.postech.ac.kr/home_2nnmeam, accessed Nov 9, 2020.
File(s):
 
Citation: W.-M. Choi, Y. Kim, D. Seol, and B.-J. Lee (2017), "Modified embedded-atom method interatomic potentials for the Co-Cr, Co-Fe, Co-Mn, Cr-Mn and Mn-Ni binary systems", Computational Materials Science, 130, 121-129. DOI: 10.1016/j.commatsci.2017.01.002.
Abstract: Interatomic potentials for the Co-Cr, Co-Fe, Co-Mn, Cr-Mn and Mn-Ni binary systems have been developed in the framework of the second nearest-neighbor modified embedded-atom method (2NN MEAM) formalism. The potentials describe various fundamental alloy behaviors (structural, elastic and thermodynamic behavior of solution and compound phases), mostly in reasonable agreements with experimental data or first-principles calculations. The potentials can be utilized to complete the interatomic potential for the CoCrFeMnNi alloy and to investigate the atomic scale physical metallurgy of high entropy alloys.

See Computed Properties
Notes: These potential files were obtained from http://cmse.postech.ac.kr/home_2nnmeam, accessed Nov 9, 2020.
File(s):
 
Citation: E. Lee, K.-R. Lee, and B.-J. Lee (2018), "An interatomic potential for the Li-Co-O ternary system", Computational Materials Science, 142, 47-58. DOI: 10.1016/j.commatsci.2017.10.010.
Abstract: Although large-scale atomistic simulations provide useful insights into various material phenomena, such studies on LiCoO2, which is the most widely used cathode material for lithium ion batteries (LIBs), have rarely been undertaken due to difficulties in developing adequate interatomic potentials. In this study, an interatomic potential (2NNMEAM + Qeq) for the Li-Co-O ternary system is developed to carry out molecular dynamics (MD) simulation studies on lithium cobalt oxides. Potential parameters are optimized so that the potential can successfully reproduce fundamental materials properties (structural, elastic, thermodynamic and migration properties) of various compounds of sub-binary and lithium cobalt ternary oxide systems. Through MD simulations, we investigate lithium diffusion properties (activation energy for lithium migration and diffusion coefficient) in layered Li1−xCoO2 (0 ≤ x ≤ 0.5) of various lithium vacancy concentrations. We find that the lithium vacancy concentration has a significant influence on the activation energy for lithium diffusion and the lithium diffusion coefficient in the Li1−xCoO2 cathode. The developed potential can be further utilized for atomistic simulation studies on other materials phenomena (phase transitions, defect formation, lithiation/delithiation, etc.) in LIB cathode materials.

hybrid/overlay coul/streitz meam (2018--Lee-E--Li-Co-O--LAMMPS--ipr1)
See Computed Properties
Notes: These files were obtained from http://cmse.postech.ac.kr/home_2nnmeam, accessed Nov 9, 2020. More information on using the 2NNMEAM-QEQ potentials can be found at https://cmse.postech.ac.kr/lammps/140341.
File(s):
 
Citation: W.-M. Choi, Y. Kim, D. Seol, and B.-J. Lee (2017), "Modified embedded-atom method interatomic potentials for the Co-Cr, Co-Fe, Co-Mn, Cr-Mn and Mn-Ni binary systems", Computational Materials Science, 130, 121-129. DOI: 10.1016/j.commatsci.2017.01.002.
Abstract: Interatomic potentials for the Co-Cr, Co-Fe, Co-Mn, Cr-Mn and Mn-Ni binary systems have been developed in the framework of the second nearest-neighbor modified embedded-atom method (2NN MEAM) formalism. The potentials describe various fundamental alloy behaviors (structural, elastic and thermodynamic behavior of solution and compound phases), mostly in reasonable agreements with experimental data or first-principles calculations. The potentials can be utilized to complete the interatomic potential for the CoCrFeMnNi alloy and to investigate the atomic scale physical metallurgy of high entropy alloys.

See Computed Properties
Notes: These potential files were obtained from http://cmse.postech.ac.kr/home_2nnmeam, accessed Nov 9, 2020.
File(s):
 
Citation: L.K. Béland, C. Lu, Y.N. Osetskiy, G.D. Samolyuk, A. Caro, L. Wang, and R.E. Stoller (2016), "Features of primary damage by high energy displacement cascades in concentrated Ni-based alloys", Journal of Applied Physics, 119(8), 085901. DOI: 10.1063/1.4942533.
Abstract: Alloying of Ni with Fe or Co has been shown to reduce primary damage production under ion irradiation. Similar results have been obtained from classical molecular dynamics simulations of 1, 10, 20, and 40 keV collision cascades in Ni, NiFe, and NiCo. In all cases, a mix of imperfect stacking fault tetrahedra, faulted loops with a 1/3⟨111⟩ Burgers vector, and glissile interstitial loops with a 1/2⟨110⟩ Burgers vector were formed, along with small sessile point defect complexes and clusters. Primary damage reduction occurs by three mechanisms. First, Ni-Co, Ni-Fe, Co-Co, and Fe-Fe short-distance repulsive interactions are stiffer than Ni-Ni interactions, which lead to a decrease in damage formation during the transition from the supersonic ballistic regime to the sonic regime. This largely controls final defect production. Second, alloying decreases thermal conductivity, leading to a longer thermal spike lifetime. The associated annealing reduces final damage production. These two mechanisms are especially important at cascades energies less than 40 keV. Third, at the higher energies, the production of large defect clusters by subcascades is inhibited in the alloys. A number of challenges and limitations pertaining to predictive atomistic modeling of alloys under high-energy particle irradiation are discussed.

Notes: Prof. Beland notes that "The potential takes elemental Ni from 2004--Mishin-Y--Ni-Al and Co from 2012--Purja-Pun-G-P-Mishin-Y--Co and mixes them. We first applied the effective gauge transformation, and then fitted the cross-term as to reproduce the heat of mixing of Ni(x)-Co(1-x). The potential is very soft at short distances. In order to perform collision cascades, it should be overlaid to the ZBL potential, with an outer cutoff of 2.0 Angstroms."

LAMMPS pair_style eam/alloy (2016--Beland-L-K--Ni-Co--LAMMPS--ipr1)
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Notes: This file was provided by Laurent Béland on 7 Nov 2019 and posted with his permission. Note: The EAM potential by itself is very soft at short distances. In order to perform collision cascades, use the hybrid style listed below.
File(s):
LAMMPS pair_style hybrid/overlay zbl eam/alloy (2016--Beland-L-K--Ni-Co--LAMMPS--ipr2)
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Notes: The eam file was provided by Laurent Béland on 7 Nov 2019 and posted with his permission. It is the same eam/alloy file as the above implementation. example.lammps.in provides an example of how to call the potential with the ZBL overlay applied.
File(s):
Citation: Y.-K. Kim, W.-S. Jung, and B.-J. Lee (2015), "Modified embedded-atom method interatomic potentials for the Ni-Co binary and the Ni-Al-Co ternary systems", Modelling and Simulation in Materials Science and Engineering, 23(5), 055004. DOI: 10.1088/0965-0393/23/5/055004.
Abstract: Interatomic potentials for the Ni-Co binary and Ni-Al-Co ternary systems have been developed on the basis of the second nearest-neighbor modified embedded-atom method (2NN MEAM) formalism. The potentials describe structural, thermodynamic, deformation and defect properties of solid solution phases or compound phases in reasonable agreements with experiments or first-principles calculations. The results demonstrate the transferability of the potentials and their applicability to large-scale atomistic simulations to investigate the effect of an alloying element, cobalt, on various microstructural factors related to mechanical properties of Ni-based superalloys on an atomic scale.

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Notes: These files are based on files obtained from http://cmse.postech.ac.kr/home_2nnmeam.
File(s):
Citation: G.P. Purja Pun, V. Yamakov, and Y. Mishin (2015), "Interatomic potential for the ternary Ni–Al–Co system and application to atomistic modeling of the B2–L10 martensitic transformation", Modelling and Simulation in Materials Science and Engineering, 23(6), 065006. DOI: 10.1088/0965-0393/23/6/065006.
Abstract: Ni–Al–Co is a promising system for ferromagnetic shape memory applications. This paper reports on the development of a ternary embedded-atom potential for this system by fitting to experimental and first-principles data. Reasonably good agreement is achieved for physical properties between values predicted by the potential and values known from experiment and/or first-principles calculations. The potential reproduces basic features of the martensitic phase transformation from the B2-ordered high-temperature phase to a tetragonal CuAu-ordered low-temperature phase. The compositional and temperature ranges of this transformation and the martensite microstructure predicted by the potential compare well with existing experimental data. These results indicate that the proposed potential can be used for simulations of the shape memory effect in the Ni–Al–Co system.

Notes: The reference information was updated on 26 Aug. 2015.

LAMMPS pair_style eam/alloy (2015--Purja-Pun-G-P--Ni-Co--LAMMPS--ipr1)
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Notes: This file was sent by Y. Mishin (George Mason Univ.) on 17 Sept. 2013 and was posted on 17 Jan. 2014. This version is compatible with LAMMPS. Validation and usage information can be found in Mishin-Ni-Co-2013_lammps.pdf.
File(s): superseded


LAMMPS pair_style eam/alloy (2015--Purja-Pun-G-P--Ni-Co--LAMMPS--ipr2)
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Notes: This file was sent by G Purja Pun (George Mason Univ.) on 12 Oct. 2015 and was posted on 15 Dec. 2015. This version corrects an issue with the cutoff distance for Co interactions that was discovered during calculations of pressure dependent elastic constants.
File(s):
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Notes: Listing found at https://openkim.org. This KIM potential is based on the files from 2015--Purja-Pun-G-P--Ni-Co--LAMMPS--ipr2.
Link(s):
 
Citation: G.-U. Jeong, C.S. Park, H.-S. Do, S.-M. Park, and B.-J. Lee (2018), "Second nearest-neighbor modified embedded-atom method interatomic potentials for the Pd-M (M = Al, Co, Cu, Fe, Mo, Ni, Ti) binary systems", Calphad, 62, 172-186. DOI: 10.1016/j.calphad.2018.06.006.
Abstract: Palladium (Pd) has attracted attention as one of the major components of noble metal catalysts due to its excellent reactivity to a wide range of catalytic reactions. It is important to predict and control the atomic arrangement in catalysts because their properties are known to be affected by it. Therefore, to enable atomistic simulations for investigating the atomic scale structural evolution, we have developed interatomic potentials for Pd-M (M = Al, Co, Cu, Fe, Mo, Ni, Ti) binary systems based on the second nearest-neighbor modified embedded-atom method formalism. These potentials reproduce various fundamental properties of the alloys (the structural, elastic and thermodynamic properties of compound and solution phases, and order-disorder transition temperature) in reasonable agreements with experimental data, first-principles calculations and CALPHAD assessments. Herein, we propose that these potentials can be applied to the design of robust bimetallic catalysts by predicting the shape and atomic arrangement of Pd bimetallic nanoparticles.

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Notes: The meam files were generated from the word file which was obtained from http://cmse.postech.ac.kr/home_2nnmeam.
File(s):
 
Citation: J.-S. Kim, D. Seol, J. Ji, H.-S. Jang, Y. Kim, and B.-J. Lee (2017), "Second nearest-neighbor modified embedded-atom method interatomic potentials for the Pt-M (M = Al, Co, Cu, Mo, Ni, Ti, V) binary systems", Calphad, 59, 131-141. DOI: 10.1016/j.calphad.2017.09.005.
Abstract: Interatomic potentials for Pt-M (M = Al, Co, Cu, Mo, Ni, Ti, V) binary systems have been developed on the basis of the second nearest-neighbor modified embedded-atom method (2NN MEAM) formalism. The parameters of pure Mo have also been newly developed to solve a problem in the previous 2NN MEAM potential in which the sigma and α-Mn structures become more stable than the bcc structure. The potentials reproduce various materials properties of alloys (structural, thermodynamic and order-disorder transition temperature) in reasonable agreements with relevant experimental data and other calculations. The applicability of the developed potentials to atomistic investigations for the shape and atomic configuration of Pt bimetallic nanoparticles is demonstrated.

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Notes: These potential files were obtained from http://cmse.postech.ac.kr/home_2nnmeam, accessed Nov 9, 2020.
File(s):
 
Citation: S.-H. Oh, D. Seol, and B.-J. Lee (2020), "Second nearest-neighbor modified embedded-atom method interatomic potentials for the Co-M (M = Ti, V) binary systems", Calphad, 70, 101791. DOI: 10.1016/j.calphad.2020.101791.
Abstract: Interatomic potentials for the Co–Ti and Co–V binary alloy systems have been developed based on the second nearest-neighbor modified embedded-atom method (2NN MEAM) interatomic potential formalism. Newly developed potentials reproduce various structural and thermodynamic properties of the binary alloys in reasonable agreement with experiments, first-principles calculations, and CALPHAD-type thermodynamic assessments. It is emphasized that these potentials can serve as groundwork for atomistic studies on the design of highly efficient trimetallic noble metal catalysts.

LAMMPS pair_style meam (2020--Oh-S-H--Co-Ti--LAMMPS--ipr1)
See Computed Properties
Notes: These potential files were obtained from http://cmse.postech.ac.kr/home_2nnmeam, accessed Nov 9, 2020.
File(s):
 
Citation: S.-H. Oh, D. Seol, and B.-J. Lee (2020), "Second nearest-neighbor modified embedded-atom method interatomic potentials for the Co-M (M = Ti, V) binary systems", Calphad, 70, 101791. DOI: 10.1016/j.calphad.2020.101791.
Abstract: Interatomic potentials for the Co–Ti and Co–V binary alloy systems have been developed based on the second nearest-neighbor modified embedded-atom method (2NN MEAM) interatomic potential formalism. Newly developed potentials reproduce various structural and thermodynamic properties of the binary alloys in reasonable agreement with experiments, first-principles calculations, and CALPHAD-type thermodynamic assessments. It is emphasized that these potentials can serve as groundwork for atomistic studies on the design of highly efficient trimetallic noble metal catalysts.

LAMMPS pair_style meam (2020--Oh-S-H--Co-V--LAMMPS--ipr1)
See Computed Properties
Notes: These potential files were obtained from http://cmse.postech.ac.kr/home_2nnmeam, accessed Nov 9, 2020.
File(s):
Date Created: October 5, 2010 | Last updated: June 09, 2022