× Updated! Potentials that share interactions are now listed as related models.
 
Citation: M.S. Nitol, D.E. Dickel, and C.D. Barrett (2022), "Machine learning models for predictive materials science from fundamental physics: An application to titanium and zirconium", Acta Materialia, 224, 117347. DOI: 10.1016/j.actamat.2021.117347.
Abstract: Here we present new neural network potentials capable of accurately modeling the transformations between the α, β, and ω phases of titanium (Ti) and zirconium (Zr), including accurate prediction of the equilibrium phase diagram. The potentials are constructed based on the rapid artificial neural network (RANN) formalism which bases its structural fingerprint on the modified embedded atom method. This implementation allows the potential to reproduce density functional theory results including elastic and plastic properties, phonon spectra, and relative energies of each of the three phases at classical molecular dynamics (MD) speeds. Transitions between each of the phase pairs are observed in dynamic simulation and, using calculations of the Gibbs free energy, both potentials are shown to accurately predict the experimentally observed phase transformation temperatures and pressures over the entire phase diagram. The calculated triple points are 8.67 GPa and 1058 K for Ti and 5.04 GPa and 988.35 K for Zr, close to their experimentally observed values. The mechanism of transformation is also observed for each phase pair. The neural network potentials can be used to further investigate the behavior of each phase and their interaction.

LAMMPS pair_style rann (2022--Nitol-M-S--Ti--LAMMPS--ipr1)
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Notes: This file and the github link were provided by Mashroor Nitol on July 13, 2023.
File(s): Link(s):
Citation: J.S. Gibson, S.G. Srinivasan, M.I. Baskes, R.E. Miller, and A.K. Wilson (2016), "A multi-state modified embedded atom method potential for titanium", Modelling and Simulation in Materials Science and Engineering, 25(1), 015010. DOI: 10.1088/1361-651x/25/1/015010.
Abstract: The continuing search for broadly applicable, predictive, and unique potential functions led to the invention of the multi-state modified embedded atom method (MS-MEAM) (Baskes et al 2007 Phys. Rev. B 75 094113). MS-MEAM replaced almost all of the prior arbitrary choices of the MEAM electron densities, embedding energy, pair potential, and angular screening functions by using first-principles computations of energy/volume relationships for multiple reference crystal structures and transformation paths connecting those reference structures. This strategy reasonably captured diverse interactions between atoms with variable coordinations in a face-centered-cubic (fcc)-stable copper system. However, a straightforward application of the original MS-MEAM framework to model technologically useful hexagonal-close-packed (hcp) metals proved elusive. This work describes the development of an hcp-stable/fcc-metastable MS-MEAM to model titanium by introducing a new angular function within the background electron density description. This critical insight enables the titanium MS-MEAM potential to reproduce first principles computations of reference structures and transformation paths extremely well. Importantly, it predicts lattice and elastic constants, defect energetics, and dynamics of non-ideal hcp and liquid titanium in good agreement with first principles computations and corresponding experiments, and often better than the three well-known literature models used as a benchmark. The titanium MS-MEAM has been made available in the Knowledgebase of Interatomic Models (https://openkim.org/) (Tadmor et al 2011 JOM 63 17).

Notes: Update Jan 14 2022: Citation information added and id updated from 2016--Gibson-J--Ti.

See Computed Properties
Notes: Listing found at https://openkim.org.
Link(s):
Citation: M.I. Mendelev, T.L. Underwood, and G.J. Ackland (2016), "Development of an interatomic potential for the simulation of defects, plasticity, and phase transformations in titanium", The Journal of Chemical Physics, 145(15), 154102. DOI: 10.1063/1.4964654.
Abstract: New interatomic potentials describing defects, plasticity, and high temperature phase transitions for Ti are presented. Fitting the martensitic hcp-bcc phase transformation temperature requires an efficient and accurate method to determine it. We apply a molecular dynamics method based on determination of the melting temperature of competing solid phases, and Gibbs-Helmholtz integration, and a lattice-switch Monte Carlo method: these agree on the hcp-bcc transformation temperatures to within 2 K. We were able to develop embedded atom potentials which give a good fit to either low or high temperature data, but not both. The first developed potential (Ti1) reproduces the hcp-bcc transformation and melting temperatures and is suitable for the simulation of phase transitions and bcc Ti. Two other potentials (Ti2 and Ti3) correctly describe defect properties and can be used to simulate plasticity or radiation damage in hcp Ti. The fact that a single embedded atom method potential cannot describe both low and high temperature phases may be attributed to neglect of electronic degrees of freedom, notably bcc has a much higher electronic entropy. A temperature-dependent potential obtained from the combination of potentials Ti1 and Ti2 may be used to simulate Ti properties at any temperature.

Notes: This listing is for the reference's potential parameter set Ti1. Dr. Mendelev provided Ti_potentials.pdf which gives a short description of the different potentials in the reference and some basic properties.

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Notes: These files were sent by M.I. Mendelev (Ames Laboratory) on 21 July 2016 and posted with his permission. Update 19 July 2021: The contact email in the file's header has been changed.
File(s):
Citation: M.I. Mendelev, T.L. Underwood, and G.J. Ackland (2016), "Development of an interatomic potential for the simulation of defects, plasticity, and phase transformations in titanium", The Journal of Chemical Physics, 145(15), 154102. DOI: 10.1063/1.4964654.
Abstract: New interatomic potentials describing defects, plasticity, and high temperature phase transitions for Ti are presented. Fitting the martensitic hcp-bcc phase transformation temperature requires an efficient and accurate method to determine it. We apply a molecular dynamics method based on determination of the melting temperature of competing solid phases, and Gibbs-Helmholtz integration, and a lattice-switch Monte Carlo method: these agree on the hcp-bcc transformation temperatures to within 2 K. We were able to develop embedded atom potentials which give a good fit to either low or high temperature data, but not both. The first developed potential (Ti1) reproduces the hcp-bcc transformation and melting temperatures and is suitable for the simulation of phase transitions and bcc Ti. Two other potentials (Ti2 and Ti3) correctly describe defect properties and can be used to simulate plasticity or radiation damage in hcp Ti. The fact that a single embedded atom method potential cannot describe both low and high temperature phases may be attributed to neglect of electronic degrees of freedom, notably bcc has a much higher electronic entropy. A temperature-dependent potential obtained from the combination of potentials Ti1 and Ti2 may be used to simulate Ti properties at any temperature.

Notes: This listing is for the reference's potential parameter set Ti2. Dr. Mendelev provided Ti_potentials.pdf which gives a short description of the different potentials in the reference and some basic properties.

See Computed Properties
Notes: These files were sent by M.I. Mendelev (Ames Laboratory) on 21 July 2016 and posted with his permission. Update 19 July 2021: The contact email in the file's header has been changed.
File(s):
Citation: M.I. Mendelev, T.L. Underwood, and G.J. Ackland (2016), "Development of an interatomic potential for the simulation of defects, plasticity, and phase transformations in titanium", The Journal of Chemical Physics, 145(15), 154102. DOI: 10.1063/1.4964654.
Abstract: New interatomic potentials describing defects, plasticity, and high temperature phase transitions for Ti are presented. Fitting the martensitic hcp-bcc phase transformation temperature requires an efficient and accurate method to determine it. We apply a molecular dynamics method based on determination of the melting temperature of competing solid phases, and Gibbs-Helmholtz integration, and a lattice-switch Monte Carlo method: these agree on the hcp-bcc transformation temperatures to within 2 K. We were able to develop embedded atom potentials which give a good fit to either low or high temperature data, but not both. The first developed potential (Ti1) reproduces the hcp-bcc transformation and melting temperatures and is suitable for the simulation of phase transitions and bcc Ti. Two other potentials (Ti2 and Ti3) correctly describe defect properties and can be used to simulate plasticity or radiation damage in hcp Ti. The fact that a single embedded atom method potential cannot describe both low and high temperature phases may be attributed to neglect of electronic degrees of freedom, notably bcc has a much higher electronic entropy. A temperature-dependent potential obtained from the combination of potentials Ti1 and Ti2 may be used to simulate Ti properties at any temperature.

Notes: This listing is for the reference's potential parameter set Ti3. Dr. Mendelev provided Ti_potentials.pdf which gives a short description of the different potentials in the reference and some basic properties.

See Computed Properties
Notes: These files were sent by M.I. Mendelev (Ames Laboratory) on 21 July 2016 and posted with his permission. Update 19 July 2021: The contact email in the file's header has been changed.
File(s):
Citation: M.I. Mendelev, T.L. Underwood, and G.J. Ackland (2016), "Development of an interatomic potential for the simulation of defects, plasticity, and phase transformations in titanium", The Journal of Chemical Physics, 145(15), 154102. DOI: 10.1063/1.4964654.
Abstract: New interatomic potentials describing defects, plasticity, and high temperature phase transitions for Ti are presented. Fitting the martensitic hcp-bcc phase transformation temperature requires an efficient and accurate method to determine it. We apply a molecular dynamics method based on determination of the melting temperature of competing solid phases, and Gibbs-Helmholtz integration, and a lattice-switch Monte Carlo method: these agree on the hcp-bcc transformation temperatures to within 2 K. We were able to develop embedded atom potentials which give a good fit to either low or high temperature data, but not both. The first developed potential (Ti1) reproduces the hcp-bcc transformation and melting temperatures and is suitable for the simulation of phase transitions and bcc Ti. Two other potentials (Ti2 and Ti3) correctly describe defect properties and can be used to simulate plasticity or radiation damage in hcp Ti. The fact that a single embedded atom method potential cannot describe both low and high temperature phases may be attributed to neglect of electronic degrees of freedom, notably bcc has a much higher electronic entropy. A temperature-dependent potential obtained from the combination of potentials Ti1 and Ti2 may be used to simulate Ti properties at any temperature.

Notes: This listing is for the reference's temperature-dependent (Tdep) potential. Dr. Mendelev provided Ti_potentials.pdf which gives a short description of the different potentials in the reference and some basic properties.

FORTRAN (2016--Mendelev-M-I--Ti-Tdep--FORTRAN--ipr1)
Notes: This file was sent by G.J. Ackland (University of Edinburgh) on 27 Sept 2016 and posted with his permission. Dr. Ackland noted that temperature-dependent potentials are also presented in the publication. This file is a fortran program that allows a user to specify a temperature and generate a potential for that temperature. The program includes comments to aid in compiling and use. Update 19 July 2021: The contact email in the file's header has been changed.
File(s):
Citation: R.S. Elliott, and A. Akerson (2015), "Efficient "universal" shifted Lennard-Jones model for all KIM API supported species".

Notes: This is the Ti 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: R.G. Hennig, T.J. Lenosky, D.R. Trinkle, S.P. Rudin, and J.W. Wilkins (2008), "Classical potential describes martensitic phase transformations between the α, β, and ω titanium phases", Physical Review B, 78(5), 054121. DOI: 10.1103/physrevb.78.054121.
Abstract: A description of the martensitic transformations between the α, β, and ω phases of titanium that includes nucleation and growth requires an accurate classical potential. Optimization of the parameters of a modified embedded atom potential to a database of density-functional calculations yields an accurate and transferable potential as verified by comparison to experimental and density-functional data for phonons, surface and stacking fault energies, and energy barriers for homogeneous martensitic transformations. Molecular-dynamics simulations map out the pressure-temperature phase diagram of titanium. For this potential the martensitic phase transformation between α and β appears at ambient pressure and 1200 K, between α and ω at ambient conditions, between β and ω at 1200 K and pressures above 8 GPa, and the triple point occurs at 8 GPa and 1200 K. Molecular-dynamics explorations of the kinetics of the martensitic α−ω transformation show a fast moving interface with a low interfacial energy of 30 meV/Å2. The potential is applicable to the study of defects and phase transformations of Ti.

LAMMPS pair_style meam/spline (2008--Hennig-R-G--Ti--LAMMPS--ipr1)
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Notes: This file was taken from the August 22, 2018 LAMMPS distribution. It is listed as being contributed by Alexander Stukowski (Technische Universität Darmstadt)
File(s):
Citation: Y.-M. Kim, B.-J. Lee, and M.I. Baskes (2006), "Modified embedded-atom method interatomic potentials for Ti and Zr", Physical Review B, 74(1), 014101. DOI: 10.1103/physrevb.74.014101.
Abstract: Semiempirical interatomic potentials for hcp elements, Ti and Zr, have been developed based on the MEAM (modified embedded-atom method) formalism. The new potentials do not cause the stability problem previously reported in MEAM for hcp elements, and describe wide range of physical properties (bulk properties, point defect properties, planar defect properties, and thermal properties) of pure Ti and Zr, in good agreement with experimental information. The applicability of the potentials to atomistic approaches for investigation of various materials behavior (slip, irradiation, amorphous behavior, etc.) in Ti or Zr-based alloys is demonstrated by showing that the related material properties are correctly reproduced using the present potentials and that the potentials can be easily extended to multicomponent systems.

LAMMPS pair_style meam (2006--Kim-Y-M--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):
See Computed Properties
Notes: Listing found at https://openkim.org.
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--Ti--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--Ti--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--Ti--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--Ti--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--Ti--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--Ti--LAMMPS--ipr2.
Link(s):
Citation: G.J. Ackland (1992), "Theoretical study of titanium surfaces and defects with a new many-body potential", Philosophical Magazine A, 66(6), 917-932. DOI: 10.1080/01418619208247999.
Abstract: It is shown that any force model using short-range pair-functional interactions can only have three independent h.c.p. elastic constants. Empirical data show that these elastic properties are nearly realized in a number of materials. A new parametrization of a Finnis-Sinclair-type many-body potential for titanium is presented using these relations. Particular care is taken to describe the anisotropy of the shear constants and the deviation of the c/a lattice parameter ratio from ideal, while maintaining smooth monotonic functions. Energies, stresses and reconstruction modes of various low-index surfaces are calculated and general rules for surface stability are proposed. Various stacking faults on the basal and pyramidal plane are investigated.

Moldy FS (1992--Ackland-G-J--Ti--MOLDY--ipr1)
Notes: The parameters in ti.moldy were obtained from http://homepages.ed.ac.uk/graeme/moldy/moldy.html and posted with the permission of G.J. Ackland (University of Edinburgh).
File(s):
LAMMPS pair_style eam/fs (1992--Ackland-G-J--Ti--LAMMPS--ipr1)
See Computed Properties
Notes: This conversion was performed from G.J. Ackland's parameters by M.I. Mendelev (Ames National Laboratory). The email address was changed from that of M.I. Mendelev to G.J. Ackland. C.A. Becker (NIST) tested the file to run with the 7Jul09 release of LAMMPS, but properties were not evaluated. This file was posted on 1 Dec. 2009 with the permission of G.J. Ackland and M.I. Mendelev.
File(s):
LAMMPS pair_style eam/fs (1992--Ackland-G-J--Ti--LAMMPS--ipr2)
See Computed Properties
Notes: A new conversion to LAMMPS performed by G.J. Ackland was submitted on 10 Oct. 2017. This version adds close-range repulsion for radiation studies.
File(s):
See Computed Properties
Notes: Listing found at https://openkim.org. This KIM potential is based on the files from 1992--Ackland-G-J--Ti--LAMMPS--ipr1.
Link(s):
 
Citation: G. Plummer, H. Rathod, A. Srivastava, M. Radovic, T. Ouisse, M. Yildizhan, P.O. Persson, K. Lambrinou, M.W. Barsoum, and G.J. Tucker (2021), "On the origin of kinking in layered crystalline solids", Materials Today, 43, 45-52. DOI: 10.1016/j.mattod.2020.11.014.
Abstract: Kinking is a deformation mechanism ubiquitous to layered systems, ranging from the nanometer scale in layered crystalline solids, to the kilometer scale in geological formations. Herein, we demonstrate its origins in the former through multiscale experiments and atomistic simulations. When compressively loaded parallel to their basal planes, layered crystalline solids first buckle elastically, then nucleate atomic-scale, highly stressed ripplocation boundaries – a process driven by redistributing strain from energetically expensive in-plane bonds to cheaper out-of-plane bonds. The consequences are far reaching as the unique mechanical properties of layered crystalline solids are highly dependent upon their ability to deform by kinking. Moreover, the compressive strength of numerous natural and engineered layered systems depends upon the ease of kinking or lack there of.

Notes: This potential was designed for studies of MAX phase deformation, with particular attention paid to replicating the characteristics of basal slip. It successfully captures MAX phase plastic anisotropy, predicting deformation by both basal slip and kinking depending on orientation. Note that this is the second iteration of the 2019--Plummer-G-Tucker-G-J--Ti-Al-C potential, developed over both publications. This iteration is more suitable for deformation studies rather than irradiation tolerance.

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Notes: This file was provided by Gabriel Plummer on March 2, 2022 and posted with his permission.
File(s):
Citation: G. Plummer, and G.J. Tucker (2019), "Bond-order potentials for the Ti3AlC2 and Ti3SiC2 MAX phases", Physical Review B, 100(21), 214114. DOI: 10.1103/physrevb.100.214114.
Abstract: Bond-order potentials have been developed for the Ti3AlC2 and Ti3SiC2 MAX phases within the Tersoff formalism. Parameters were determined by independently considering each interatomic interaction present in the system and fitting them to the relevant structural, elastic, and defect properties for a number of unary, binary, and ternary structures. A number of material properties, including those not used in the fitting procedure, are reproduced with a high degree of accuracy when compared to experiment and ab initio calculations. Additionally, well-documented MAX phase behaviors such as plastic anisotropy and kinking nonlinear elasticity are demonstrated to be captured by the potentials. As a first highly accurate atomistic model for MAX phases, these potentials provide the opportunity to study some of the fundamental mechanisms behind unique MAX phase properties. Additionally, the fitting procedure employed is highly transferable and should be applicable to numerous other MAX phases.

Notes: This potential was designed for the study of MAX phases. In comparison to 2021--Plummer-G-Rathod-H-Srivastava-A-et-al--Ti-Al-C, this parameterization of Ti3AlC2 is more suitable for studies of irradiation tolerance rather than deformation.

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Notes: This file was taken from the supplementary material of the associated paper and posted with Gabriel Plummer's permission.
File(s):
 
Citation: R. Fereidonnejad, A.O. Moghaddam, and M. Moaddeli (2022), "Modified embedded-atom method interatomic potentials for Al-Ti, Al-Ta, Al-Zr, Al-Nb and Al-Hf binary intermetallic systems", Computational Materials Science, 213, 111685. DOI: 10.1016/j.commatsci.2022.111685.
Abstract: Interatomic potentials for the Al-Ti, Al-Ta, Al-Zr, Al-Nb and Al-Hf binary systems have been developed based on the second nearest-neighbor modified embedded-atom method (2NN MEAM) formalism. The fundamental materials properties (structural, thermodynamic and elastic behaviors of different intermetallics) could be readily described with the potentials using molecular dynamic simulation (MD), in rational agreements with experimental or first principles data. The potentials are further utilized to develop an interatomic potential for the (TiZrNbHfTa)Al3 high entropy intermetallic compound (HEIC), which open the door to understand atomic scale behavior of HEICs.

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Notes: These files were provided by Rahele Fereidonnejad on November 30, 2023.
File(s):
 
Citation: D. Farkas, and C. Jones (1996), "Interatomic potentials for ternary Nb - Ti - Al alloys", Modelling and Simulation in Materials Science and Engineering, 4(1), 23-32. DOI: 10.1088/0965-0393/4/1/004.
Abstract: Interatomic potentials of the embedded-atom type were developed for the Nb - Al system via an empirical fitting to the properties of A15 Nb3Al. The cohesive energy and lattice parameters are fitted by the potentials, which also give good agreement with experimental values for the same properties in the D022 NbAl3 phase. A second interatomic potential was developed for the Nb - Ti system via a fitting to the lattice parameters and thermodynamic properties of the disordered BCC phase. The Al and Ti potentials used here are the same as those used in our previous work to derive Ti - Al potentials based on TiAl. This allows the use of the present potentials in conjunction with those previously derived interactions to study ternary Nb - Ti - Al alloys. The potentials were used to calculate the heats of solution of Al and Ti in Nb, and to simulate the Ti2NbAl orthorhombic phase.

LAMMPS pair_style eam/alloy (1996--Farkas-D--Nb-Ti-Al--LAMMPS--ipr1)
See Computed Properties
Notes: This file was generated and tested by Ganga Purja Pun and Yuri Mishin (George Mason Univ.) using the files below that were supplied by Diana Farkas (Virginia Tech.). Testing information is in Test_report_AlTiNb.pdf. These files were approved by Dr. Purja Pun and Profs. Farkas and Mishin and posted on 1 Jul 2014.
File(s):
EAM tabulated functions (1996--Farkas-D--Nb-Ti-Al--table--ipr1)
Notes: These files were provided by Diana Farkas and approved by her on 1 Jul 2014.
File(s):
See Computed Properties
Notes: Listing found at https://openkim.org. This KIM potential is based on the files from 1996--Farkas-D--Nb-Ti-Al--LAMMPS--ipr1.
Link(s):
 
Citation: Y.-K. Kim, H.-K. Kim, W.-S. Jung, and B.-J. Lee (2017), "Development and application of Ni-Ti and Ni-Al-Ti 2NN-MEAM interatomic potentials for Ni-base superalloys", Computational Materials Science, 139, 225-233. DOI: 10.1016/j.commatsci.2017.08.002.
Abstract: Interatomic potentials for the Ni-Ti and Ni-Al-Ti systems have been developed based on the second nearest-neighbor modified embedded-atom method (2NN-MEAM) formalism. The Ni-Ti binary potential reproduces fundamental materials properties (structural, elastic, thermodynamic, and thermal stability) of alloy systems in reasonable agreement with experiments, first-principles calculations and thermodynamic calculations. Atomistic simulations using the Ni-Al-Ti ternary potential validate that the potential can be applied successfully to atomic-scale investigations to clarify the effects of titanium on important materials phenomena (site preference in γ', γ-γ' phase transition, and segregation on grain boundaries) in Ni-Al-Ti ternary superalloys.

See Computed Properties
Notes: These potential files were obtained from http://cmse.postech.ac.kr/home_2nnmeam, accessed Nov 9, 2020.
File(s):
 
Citation: R. Fereidonnejad, A.O. Moghaddam, and M. Moaddeli (2022), "Modified embedded-atom method interatomic potentials for Al-Ti, Al-Ta, Al-Zr, Al-Nb and Al-Hf binary intermetallic systems", Computational Materials Science, 213, 111685. DOI: 10.1016/j.commatsci.2022.111685.
Abstract: Interatomic potentials for the Al-Ti, Al-Ta, Al-Zr, Al-Nb and Al-Hf binary systems have been developed based on the second nearest-neighbor modified embedded-atom method (2NN MEAM) formalism. The fundamental materials properties (structural, thermodynamic and elastic behaviors of different intermetallics) could be readily described with the potentials using molecular dynamic simulation (MD), in rational agreements with experimental or first principles data. The potentials are further utilized to develop an interatomic potential for the (TiZrNbHfTa)Al3 high entropy intermetallic compound (HEIC), which open the door to understand atomic scale behavior of HEICs.

See Computed Properties
Notes: These files were provided by Rahele Fereidonnejad on August 24, 2022.
File(s):
Citation: Y.-K. Kim, H.-K. Kim, W.-S. Jung, and B.-J. Lee (2016), "Atomistic modeling of the Ti–Al binary system", Computational Materials Science, 119, 1-8. DOI: 10.1016/j.commatsci.2016.03.038.
Abstract: An interatomic potential for the Ti–Al binary system has been developed based on the second nearest-neighbor modified embedded-atom method (2NN MEAM) formalism. This potential describes fundamental materials properties (structural, thermodynamic, elastic, defect, deformation and thermal properties) of Ti–Al alloys in good agreements with experimental or first-principles data. The transferability and applicability of the present potential to atomic-scale investigations for Ni-based superalloys or Ti–Al based alloys are demonstrated.

See Computed Properties
Notes: These potential files were obtained from http://cmse.postech.ac.kr/home_2nnmeam, accessed Nov 9, 2020.
File(s):
Citation: R.R. Zope, and Y. Mishin (2003), "Interatomic potentials for atomistic simulations of the Ti-Al system", Physical Review B, 68(2), 024102. DOI: 10.1103/physrevb.68.024102.
Abstract: Semiempirical interatomic potentials have been developed for Al, α−Ti, and γ−TiAl within the embedded atom method (EAM) formalism by fitting to a large database of experimental as well as ab initio data. The ab initio calculations were performed by the linearized augmented plane wave (LAPW) method within the density functional theory to obtain the equations of state for a number of crystal structures of the Ti-Al system. Some of the calculated LAPW energies were used for fitting the potentials while others for examining their quality. The potentials correctly predict the equilibrium crystal structures of the phases and accurately reproduce their basic lattice properties. The potentials are applied to calculate the energies of point defects, surfaces, and planar faults in the equilibrium structures. Unlike earlier EAM potentials for the Ti-Al system, the proposed potentials provide a reasonable description of the lattice thermal expansion, demonstrating their usefulness for molecular-dynamics and Monte Carlo simulations at high temperatures. The energy along the tetragonal deformation path (Bain transformation) in γ−TiAl calculated with the EAM potential is in fairly good agreement with LAPW calculations. Equilibrium point defect concentrations in γ−TiAl are studied using the EAM potential. It is found that antisite defects strongly dominate over vacancies at all compositions around stoichiometry, indicating that γ−TiAl is an antisite disorder compound, in agreement with experimental data.

EAM tabulated functions (2003--Zope-R-R--Ti-Al--table--ipr1)
Notes: These files were provided by Yuri Mishin.
File(s):
Al F(ρ): F_al.plt
Ti F(ρ): F_ti.plt
Al ρ(r): fal.plt
Ti ρ(r): fti.plt
Al φ(r): pal.plt
Ti φ(r): pti.plt
Ti-Al φ(r): ptial.plt

LAMMPS pair_style eam/alloy (2003--Zope-R-R--Ti-Al--LAMMPS--ipr1)
See Computed Properties
Notes: This conversion was produced by Chandler Becker on 26 Sept. 2009 from the plt files listed above. This version is compatible with LAMMPS. Validation and usage information can be found in Zope-Ti-Al-2003_releaseNotes_1.pdf.
File(s):
See Computed Properties
Notes: Listing found at https://openkim.org. This KIM potential is based on the files from 2003--Zope-R-R--Ti-Al--LAMMPS--ipr1.
Link(s):
 
Citation: H.-K. Kim, W.-S. Jung, and B.-J. Lee (2009), "Modified embedded-atom method interatomic potentials for the Fe-Ti-C and Fe-Ti-N ternary systems", Acta Materialia, 57(11), 3140-3147. DOI: 10.1016/j.actamat.2009.03.019.
Abstract: Modified embedded-atom method (MEAM) interatomic potentials for the Fe-Ti-C and Fe-Ti-N ternary systems have been developed based on the previously developed MEAM potentials for sub-unary and binary systems. An attempt was made to find a way to determine ternary potential parameters using the corresponding binary parameters. The calculated coherent interface properties, interfacial energy, work of separation and misfit strain energy between body-centered cubic Fe and NaCl-type TiC or TiN were reasonable when compared with relevant first-principles calculations under the same condition. The applicability of the present potentials for atomistic simulations to investigate nucleation kinetics of TiC or TiN precipitates and their effects on mechanical properties in steels is also demonstrated.

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Notes: This file was submitted by Sebastián ECHEVERRI RESTREPO (SKF Engineering & Research Centre) on 31 August 2015 and approved for distribution by Byeong-Joo Lee (POSTECH). This version is compatible with LAMMPS. Implementation information can be found in FeTiC_Implementation.pdf.
File(s):
See Computed Properties
Notes: Listing found at https://openkim.org.
Link(s):
 
Citation: G. Plummer, and G.J. Tucker (2019), "Bond-order potentials for the Ti3AlC2 and Ti3SiC2 MAX phases", Physical Review B, 100(21), 214114. DOI: 10.1103/physrevb.100.214114.
Abstract: Bond-order potentials have been developed for the Ti3AlC2 and Ti3SiC2 MAX phases within the Tersoff formalism. Parameters were determined by independently considering each interatomic interaction present in the system and fitting them to the relevant structural, elastic, and defect properties for a number of unary, binary, and ternary structures. A number of material properties, including those not used in the fitting procedure, are reproduced with a high degree of accuracy when compared to experiment and ab initio calculations. Additionally, well-documented MAX phase behaviors such as plastic anisotropy and kinking nonlinear elasticity are demonstrated to be captured by the potentials. As a first highly accurate atomistic model for MAX phases, these potentials provide the opportunity to study some of the fundamental mechanisms behind unique MAX phase properties. Additionally, the fitting procedure employed is highly transferable and should be applicable to numerous other MAX phases.

Notes: This potential was designed for the study of MAX phases.

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Notes: This file was taken from the supplementary material of the associated paper and posted with Gabriel Plummer's permission.
File(s):
 
Citation: Y.-M. Kim, and B.-J. Lee (2008), "Modified embedded-atom method interatomic potentials for the Ti-C and Ti-N binary systems", Acta Materialia, 56(14), 3481-3489. DOI: 10.1016/j.actamat.2008.03.027.
Abstract: Modified embedded-atom method (MEAM) interatomic potentials for the Ti-C and Ti-N binary systems have been developed using previously developed MEAM potentials of Ti, C and N. The potential parameters were determined by fitting to experimental data on the enthalpy of formation, lattice parameter, elastic constants, thermal linear expansion of NaCl-type TiC and TiN, and dilute heat of solution of carbon and nitrogen atoms in hexagonal close-packed Ti. The potentials can describe fundamental physical properties (structural, elastic, thermal and surface properties) of the alloys well, in good agreement with experimental information or first-principles calculations. The applicability of the potentials to atomistic investigations of interactions between TiC or TiN precipitates and matrix, dislocations or other defects, and their effects on deformation and mechanical behaviors of metallic alloys is discussed.

LAMMPS pair_style meam (2008--Kim-Y-M--Ti-C--LAMMPS--ipr1)
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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: A. Liang, D.C. Goodelman, A.M. Hodge, D. Farkas, and P.S. Branicio (2023), "CoFeNiTix and CrFeNiTix high entropy alloy thin films microstructure formation", Acta Materialia, 257, 119163. DOI: 10.1016/j.actamat.2023.119163.
Abstract: High entropy alloys (HEA) composition-structure relationships are crucial for guiding their design and applications. Here, we use a combined experimental and molecular dynamics (MD) approach to investigate phase formation during physical vapor deposition (PVD) of CoFeNiTix and CrFeNiTix HEA thin films. We vary titanium molar ratio from 0 to 1 to understand the role of a larger element in the alloy mixture. The experiments show that a high titanium content favors amorphous phase formation in the samples produced by magnetron co-sputtering. In contrast, a low titanium content results in the formation of a face-centered cubic (FCC) structure in both HEA families. This effect of titanium content on the stability of the amorphous and FCC phases is reproduced in PVD MD simulations. The threshold titanium molar ratio is identified to be ~0.53 and ~0.16 for the CoFeNiTix and CrFeNiTix films in the experiments, and ~0.53 and ~0.53 in the MD simulations. In addition, the atomistic modeling allows for energy versus volume calculations with increasing titanium content, which demonstrate the stabilization of the amorphous phase with respect to crystalline structures. To isolate the effect of atomic sizes, additional simulations are performed using an average-atom model, which disregards differences in atomic radii while preserving the average properties of the alloy. In these simulations, the energetic stability of the amorphous phase disappears. The combined experimental and simulation results demonstrate that the formation of the amorphous phase in HEA thin films generated by PVD is directly caused by the atomic size difference.

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Notes: This file was provided by Diana Farkas on January 12, 2024.
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)
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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: A.S.M. Miraz, N. Dhariwal, W.J. Meng, B.R. Ramachandran, and C.D. Wick (2020), "Development and application of interatomic potentials to study the stability and shear strength of Ti/TiN and Cu/TiN interfaces", Materials & Design, 196, 109123. DOI: 10.1016/j.matdes.2020.109123.
Abstract: A modified embedded atom method interatomic potential was developed to study semi-coherent metal/ceramic interfaces involving Cu, Ti and N. A genetic algorithm was used to fit the model parameters to the physical properties of the materials. To accurately describe interfacial interactions and shear, two-dimensional generalized stacking fault energy profiles for relevant slip systems were selected as one of the major parameterization targets for the models. The models were applied to study semi-coherent Ti(0001)/TiN(111) and Cu(111)/TiN(111) systems. Ti/TiN was stable with misfits accommodated away from the interface. Cu/TiN, in contrast, was more stable with misfits at the interface. A spiral pattern in the misfit dislocation networks was observed away from the Cu/TiN interface, similar to the metal/metal (111) semi-coherent interfaces. The theoretical shear strength calculated for Ti/TiN when the misfits were several layers away from the interface and for Cu/TiN with the misfit at the chemical interface, had reasonable agreement with experiment.

Notes: Abu Shama M Miraz notes: "Our potential is mainly focused on the mechanical response of semi-coherent Ti/TiN and Cu/TiN metal/ceramic interfacial systems. We have separately parameterized to pure Cu and Ti first. So the models are good to use for these pure elements alone, if one wishes. Next, the binary Cu-Ti, Ti-N and Cu-N were fit to the model. And finally, the ternary Cu-Ti-N potential was fit to Cu/TiN metal/ceramic interfacial systems of different orientation relations. The properties that were fit can be found in the paper."

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Notes: These files were provided by Abu Shama M Miraz (Louisiana Tech) on Sept. 18, 2020 and posted with his permission.
File(s):
 
Citation: I. Sa, and B. Lee (2008), "Modified embedded-atom method interatomic potentials for the Fe–Nb and Fe–Ti binary systems", Scripta Materialia, 59(6), 595-598. DOI: 10.1016/j.scriptamat.2008.05.007.
Abstract: A semi-empirical interatomic potential formalism, the second-nearest-neighbor modified embedded-atom method (2NN MEAM), has been applied to obtain interatomic potentials for Fe–Nb and Fe–Ti systems based on the previously developed potentials for pure Fe, Nb and Ti. The present potentials generally reproduce the fundamental physical properties of the Fe–Nb and Fe–Ti systems accurately. The potentials can be easily combined with already-developed MEAM potentials for binary carbide or nitride systems and can be used to describe Fe–(Ti,Nb)–(C,N) multicomponent systems.

LAMMPS pair_style meam (2008--Sa-I--Fe-Ti--LAMMPS--ipr1)
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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: X. Huang, L. Liu, X. Duan, W. Liao, J. Huang, H. Sun, and C. Yu (2021), "Atomistic simulation of chemical short-range order in HfNbTaZr high entropy alloy based on a newly-developed interatomic potential", Materials & Design, 202, 109560. DOI: 10.1016/j.matdes.2021.109560.
Abstract: Chemical short-range order (CSRO) in high entropy alloys (HEAs) has attracted interests recently and is believed to be capable for tuning their mechanical properties. However, the characterization of CSRO in HEAs through experimental methods remains challenging. In this work, a modified embedded-atom method interatomic potential with good accuracy for studying CSRO in HfNbTaTiZr alloy system was developed. By employing the potential, molecular dynamic/Monte Carlo simulation was performed to investigate the CSRO in HfNbTaZr HEA. The results indicated that Hf-Zr and Nb-Ta atom pairs were preferred in the BCC solid solution of HfNbTaZr, and a new type of CSRO with topological B2 order was predicted, which can help to understand the mechanical properties of HfNbTaZr HEA. It was also found that forming of CSRO was an incubation process for the precipitation in HfNbTaZr, implying the significance of CSRO on the phase stability or precipitation behavior of HEAs. The findings in the present work can help in understanding CSRO and establishing its relationship with precipitates in HEAs, and more topics related to CSRO and phase stability in HfNbTaTiZr alloy system can be further investigated by atomistic simulation.

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Notes: These files were provided by Xiusong Huang (Shenzhen University) on May 5, 2021 and posted with his permission.
File(s):
 
Citation: Y.-M. Kim, and B.-J. Lee (2008), "Modified embedded-atom method interatomic potentials for the Ti-C and Ti-N binary systems", Acta Materialia, 56(14), 3481-3489. DOI: 10.1016/j.actamat.2008.03.027.
Abstract: Modified embedded-atom method (MEAM) interatomic potentials for the Ti-C and Ti-N binary systems have been developed using previously developed MEAM potentials of Ti, C and N. The potential parameters were determined by fitting to experimental data on the enthalpy of formation, lattice parameter, elastic constants, thermal linear expansion of NaCl-type TiC and TiN, and dilute heat of solution of carbon and nitrogen atoms in hexagonal close-packed Ti. The potentials can describe fundamental physical properties (structural, elastic, thermal and surface properties) of the alloys well, in good agreement with experimental information or first-principles calculations. The applicability of the potentials to atomistic investigations of interactions between TiC or TiN precipitates and matrix, dislocations or other defects, and their effects on deformation and mechanical behaviors of metallic alloys is discussed.

LAMMPS pair_style meam (2008--Kim-Y-M--Ti-N--LAMMPS--ipr1)
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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: M.S. Nitol, M.J. Echeverria, K. Dang, M.I. Baskes, and S.J. Fensin (2024), "New modified embedded-atom method interatomic potential to understand deformation behavior in VNbTaTiZr refractory high entropy alloy", Computational Materials Science, 237, 112886. DOI: 10.1016/j.commatsci.2024.112886.
Abstract: High Entropy Alloys (HEAs) have attracted much interest over the past 20 years because of their remarkable mechanical properties. Recent works on BCC refractory HEAs have demonstrated high strength even at extreme temperatures with an unusual mix of strength and ductility. They also show excellent strain-hardening behavior. This study focuses on the VNbTaTiZr alloy, which stands out for its favorable qualities including relatively low density, impressive yield strength, and ductility at room temperature. To better understand the atomic behavior and microstructural features inherent to this alloy, a Modified Embedded Atom Method (MEAM) potential is developed, based on first-principles computations. Through accurate modeling of lattice constants, elastic constants, and formation enthalpies, a hybrid Molecular Dynamics/Monte Carlo (MD/MC) simulation of an equimolar VNbTaTiZr refractory HEA was performed to explore the role of local chemical compositions to its mechanical response. The current MEAM potential aligns closely with recent experimental work, validating its effectiveness. Adding Zr to the VNbTaTi alloy induces more lattice distortion, matching recent experimental observations. The potential also predicts that for RHEAs, deformation behavior is dominated by edge dislocations, unlike in pure BCC elements where screw dislocations prevail. Overall, this potential will be useful for unraveling the intricate atomic-level processes that give this alloy its remarkable mechanical performance.

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Notes: This file was provided by Mashroor Nitol on February 28, 2024.
File(s):
 
Citation: H. Tang, Y. Zhang, Q. Li, H. Xu, Y. Wang, Y. Wang, and J. Li (2022), "High accuracy neural network interatomic potential for NiTi shape memory alloy", Acta Materialia, 118217. DOI: 10.1016/j.actamat.2022.118217.
Abstract: Nickel-titanium (NiTi) shape memory alloys (SMA) are widely used, however simulating the martensitic transformation of NiTi from first principles remains challenging. In this work, we developed a neural network interatomic potential (NNIP) for near-equiatomic Ni-Ti system through active-learning based acquisitions of density functional theory (DFT) training data, which achieves state-of-the-art accuracy. Phonon dispersion and potential-of-mean-force calculations of the temperature-dependent free energy have been carried out. This NNIP predicts temperature-induced, stress-induced, and deformation twinning-induced martensitic transformations from atomic simulations, in significant agreement with experiments. The NNIP can directly simulate the superelasticity of NiTi nanowires, providing a tool to guide their design.

Notes: This is an alternate parameterization of the potential listed in the paper. The developers note that "although v2 appears better for more general scenarios according to our tests, there are still a few cases where v1 is more accurate". This potential was designed for equiatomic NiTi shape memory alloy and can be used for NiTi alloy with slight off-stoichiometry. The potential should not be used for pure Ni, pure Ti, or Ni-Ti alloy far from the equiatomic composition.

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Notes: These files were provided by Hao Tang on August 3, 2022. Detailed instructions on using this potential in MD simulations can be found at the link below. We suggest users compress the model (see the documentation) before using it for MD simulation, as this will make the calculation significantly faster with limited influence on accuracy.
File(s): Link(s):
Citation: H. Tang, Y. Zhang, Q. Li, H. Xu, Y. Wang, Y. Wang, and J. Li (2022), "High accuracy neural network interatomic potential for NiTi shape memory alloy", Acta Materialia, 118217. DOI: 10.1016/j.actamat.2022.118217.
Abstract: Nickel-titanium (NiTi) shape memory alloys (SMA) are widely used, however simulating the martensitic transformation of NiTi from first principles remains challenging. In this work, we developed a neural network interatomic potential (NNIP) for near-equiatomic Ni-Ti system through active-learning based acquisitions of density functional theory (DFT) training data, which achieves state-of-the-art accuracy. Phonon dispersion and potential-of-mean-force calculations of the temperature-dependent free energy have been carried out. This NNIP predicts temperature-induced, stress-induced, and deformation twinning-induced martensitic transformations from atomic simulations, in significant agreement with experiments. The NNIP can directly simulate the superelasticity of NiTi nanowires, providing a tool to guide their design.

Notes: This is the parameterization of the potential as used by the associated publication. This potential was designed for equiatomic NiTi shape memory alloy and can be used for NiTi alloy with slight off-stoichiometry. The potential should not be used for pure Ni, pure Ti, or Ni-Ti alloy far from the equiatomic composition.

See Computed Properties
Notes: These files were provided by Hao Tang on August 3, 2022. Detailed instructions on using this potential in MD simulations can be found at the link below. We suggest users compress the model (see the documentation) before using it for MD simulation, as this will make the calculation significantly faster with limited influence on accuracy.
File(s): Link(s):
Citation: S. Kavousi, B.R. Novak, M.I. Baskes, M. Asle Zaeem, and D. Moldovan (2019), "Modified embedded-atom method potential for high-temperature crystal-melt properties of Ti–Ni alloys and its application to phase field simulation of solidification", Modelling and Simulation in Materials Science and Engineering, 28(1), 015006. DOI: 10.1088/1361-651x/ab580c.
Abstract: We developed new interatomic potentials, based on the second nearest-neighbor modified embedded-atom method (2NN-MEAM) formalism, for Ti, Ni, and the binary Ti–Ni system. These potentials were fit to melting points, latent heats, the binary phase diagrams for the Ti rich and Ni rich regions, and the liquid phase enthalpy of mixing for binary alloys, therefore they are particularly suited for calculations of crystal-melt (CM) interface thermodynamic and transport properties. The accuracy of the potentials for pure Ti and pure Ni were tested against both 0 K and high temperature properties by comparing various properties obtained from experiments or density functional theory calculations including structural properties, elastic constants, point-defect properties, surface energies, temperatures and enthalpies of phase transformations, and diffusivity and viscosity in the liquid phase. The fitted binary potential for Ti–Ni was also tested against various non-fitted properties at 0 K and high temperatures including lattice parameters, formation energies of different intermetallic compounds, and the temperature dependence of liquid density at various concentrations. The CM interfacial free energies obtained from simulations, based on the newly developed Ti–Ni potential, show that the bcc alloys tend to have smaller anisotropy compared with fcc alloys which is consistent with the finding from the previous studies comparing single component bcc and fcc materials. Moreover, the interfacial free energy and its anisotropy for Ti-2 atom% Ni were also used to parameterize a 2D phase field (PF) model utilized in solidification simulations. The PF simulation predictions of microstructure development during solidification are in good agreement with a geometric model for dendrite primary arm spacing.

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Notes: This file was sent by Sepideh Kavousi (Colorado School of Mines) on 10 Nov. 2020 and posted with her permission.
File(s):
Citation: Y.-K. Kim, H.-K. Kim, W.-S. Jung, and B.-J. Lee (2017), "Development and application of Ni-Ti and Ni-Al-Ti 2NN-MEAM interatomic potentials for Ni-base superalloys", Computational Materials Science, 139, 225-233. DOI: 10.1016/j.commatsci.2017.08.002.
Abstract: Interatomic potentials for the Ni-Ti and Ni-Al-Ti systems have been developed based on the second nearest-neighbor modified embedded-atom method (2NN-MEAM) formalism. The Ni-Ti binary potential reproduces fundamental materials properties (structural, elastic, thermodynamic, and thermal stability) of alloy systems in reasonable agreement with experiments, first-principles calculations and thermodynamic calculations. Atomistic simulations using the Ni-Al-Ti ternary potential validate that the potential can be applied successfully to atomic-scale investigations to clarify the effects of titanium on important materials phenomena (site preference in γ', γ-γ' phase transition, and segregation on grain boundaries) in Ni-Al-Ti ternary superalloys.

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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: W.-S. Ko, B. Grabowski, and J. Neugebauer (2015), "Development and application of a Ni-Ti interatomic potential with high predictive accuracy of the martensitic phase transition", Physical Review B, 92(13), 134107. DOI: 10.1103/physrevb.92.134107.
Abstract: Phase transitions in nickel-titanium shape-memory alloys are investigated by means of atomistic simulations. A second nearest-neighbor modified embedded-atom method interatomic potential for the binary nickel-titanium system is determined by improving the unary descriptions of pure nickel and pure titanium, especially regarding the physical properties at finite temperatures. The resulting potential reproduces accurately the hexagonal-close-packed to body-centered-cubic phase transition in Ti and the martensitic B2−B19′ transformation in equiatomic NiTi. Subsequent large-scale molecular-dynamics simulations validate that the developed potential can be successfully applied for studies on temperature- and stress-induced martensitic phase transitions related to core applications of shape-memory alloys. A simulation of the temperature-induced phase transition provides insights into the effect of sizes and constraints on the formation of nanotwinned martensite structures with multiple domains. A simulation of the stress-induced phase transition of a nanosized pillar indicates a full recovery of the initial structure after the loading and unloading processes, illustrating a superelastic behavior of the target system.

LAMMPS pair_style meam (2015--Ko-W-S--Ni-Ti--LAMMPS--ipr2)
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Notes: These files were sent by Won-Seok Ko (University of Ulsan, South Korea) on 24 July 2016 and posted with his permission.
File(s):
 
Citation: S.B. Maisel, W.-S. Ko, J.-L. Zhang, B. Grabowski, and J. Neugebauer (2017), "Thermomechanical response of NiTi shape-memory nanoprecipitates in TiV alloys", Physical Review Materials, 1(3), 033610. DOI: 10.1103/physrevmaterials.1.033610.
Abstract: We study the properties of NiTi shape-memory nanoparticles coherently embedded in TiV matrices using three-dimensional atomistic simulations based on the modified embedded-atom method. To this end, we develop and present a suitable NiTiV potential for our simulations. Employing this potential, we identify the conditions under which the martensitic phase transformation of such a nanoparticle is triggered—specifically, how these conditions can be tuned by modifying the size of the particle, the composition of the surrounding matrix, or the temperature and strain state of the system. Using these insights, we establish how the transformation temperature of such particles can be influenced and discuss the practical implications in the context of shape-memory strengthened alloys.

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Notes: These files were sent by Won-Seok Ko (School of Materials Science and Engineering, University of Ulsan) on 9 Feb. 2018 and posted with his permission.
File(s):
 
Citation: E. Lee, K.-R. Lee, M.I. Baskes, and B.-J. Lee (2016), "A modified embedded-atom method interatomic potential for ionic systems: 2NNMEAM+Qeq", Physical Review B, 93(14), 144110. DOI: 10.1103/physrevb.93.144110.
Abstract: An interatomic potential model that can simultaneously describe metallic, covalent, and ionic bonding is suggested by combining the second nearest-neighbor modified embedded-atom method (2NNMEAM) and the charge equilibration (Qeq) method, as a further improvement of a series of existing models. Paying special attention to the removal of known problems found in the original Qeq model, a mathematical form for the atomic energy is newly developed, and carefully selected computational techniques are adapted for energy minimization, summation of Coulomb interaction, and charge representation. The model is applied to the Ti-O and Si-O binary systems selected as representative oxide systems for a metallic element and a covalent element. The reliability of the present 2NNMEAM+Qeq potential is evaluated by calculating the fundamental physical properties of a wide range of titanium and silicon oxides and comparing them with experimental data, density functional theory calculations, and other calculations based on (semi-)empirical potential models.

hybrid/overlay coul/streitz meam (2016--Lee-E--Ti-O--LAMMPS--ipr1)
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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: P. Zhang, and D.R. Trinkle (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: Prof. Trinkle said that this potential is specifically intended for dilute oxygen in titanium as there's no oxygen-oxygen interaction. 9 Aug. 2016: the reference information was updated.

MEAM splines (2016--Zhang-P--Ti-O--table--ipr1)
Notes: This file was sent by Prof. Dallas Trinkle (Univ. of Illinois) on 6 Aug. 2016 and posted with his permission. Update 2018-11-06: file format changed to reflect that it does not work with LAMMPS.
File(s): superseded


MEAM splines (2016--Zhang-P--Ti-O--table--ipr2)
Notes: This file was sent by Prof. Dallas Trinkle (Univ. of Illinois) on 9 Aug. 2016 and posted with his permission. This version removes an extra comment line that was not compatible with the LAMMPS MEAM/spline code. Update 2018-11-06: file format changed to reflect that it does not work with LAMMPS (see version below).
File(s): superseded


LAMMPS pair_style meam/spline (2016--Zhang-P--Ti-O--LAMMPS--ipr1)
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Notes: This file was taken from the August 22, 2018 LAMMPS distribution. It has a slightly different header section from the above versions allowing it to work in the official multi-element meam/spline implementation. This version successfully ran with the stable March 16, 2018 and August 22, 2018 LAMMPS versions.
File(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: P. Wang, Y. Bu, J. Liu, Q. Li, H. Wang, and W. Yang (2020), "Atomic deformation mechanism and interface toughening in metastable high entropy alloy", Materials Today, 37, 64-73. DOI: 10.1016/j.mattod.2020.02.017.
Abstract: Metastable high entropy alloy (HEA) with excellent properties have attracted extensive attentions recently. However, as a consequence of limited experiments of high-resolution transmission electron microscopy (HRTEM) and the difficulties of molecular dynamic (MD) simulations for the phase transformation process, the detailed atomic deformation mechanisms in the HEA is not well understood. We carry out the in situ HRTEM observation of the martensitic transformation process and find surprisingly wide phase interface between the parent and the martensite in a typical high strength and high elongation metastable HEA. One specific interatomic potential is developed for the metastable HEA and large-scale MD simulation is carried out to investigate the martensitic transformation process from body-centered cubic to hexagonal close packed structures. The whole processes of the stress-induced martensitic transformation (nucleation, incubation, bursting and propagating of the new phase) are well reproduced in the MD simulations, suggesting its good agreements with the HRTEM observations. The width of the phase interface mainly depends on the competition between interfacial energy and lattice distortion energy during the martensitic transformation process. This wide phase interface acts as a buffer to coordinate the martensitic transformation induced strain and as a buffer storage for dislocation gliding and pile-up. As a result, the metastable HEA achieves a high strength combined with a large tensile elongation. The revealed atomic-scale deformation and corresponding interatomic potential should be useful to guide the design in the new series of high-performance metastable alloy.

Notes: Dr. Peng Wang notes that "This potential is developed base on the framework of meta-atom method which focuses on the direct relationship between material properties and their deformation mechanisms. In this method, a detailed distinction among various atomic species is discarded and an alloy system is represented by a set of meta-atom which is fitted to all related material properties. Once the completeness of material properties is established, two systems with the same properties are expected to deform identically. This method has been verified to be able to describe the mechanical behavior of binary alloys and multi-element alloys by different groups."

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Notes: This file was sent by P. Wang (Shanghai University) on 12 Oct. 2020 and posted with his permission.
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Date Created: October 5, 2010 | Last updated: March 01, 2024