This directory contains potential files for different elements and alloys, as used by LAMMPS for various pair styles. See the description of the "pair_style" and "pair_coeff" commands for details of the file formats and the various styles in LAMMPS that read these files.

IMPORTANT NOTE: These files are provided primarily to demonstrate the different types of interatomic potentials that LAMMPS supports. Each file has a header line with a date for when it was added to the LAMMPS distribution. Also a citation and contact info for the person who contributed it to LAMMPS (if we remember who that is). This info is not meant to "guarantee" that the potential is correct. I.e. that the contributor transcribed the info from the paper correctly or that the paper itself had no errors. In many cases (but not all), we or other LAMMPS users have confirmed that when the potential file is used with the current version of LAMMPS, it reproduces results in the cited publication. In some cases, this accuracy check may require other parameters not contained in the potential file to be specified as part of a LAMMPS simulation, e.g. a distance cutoff. Also, for particular materials and applications modeled with a pair style coded in LAMMPS, a different potential file may be more suitable than the one provided here. For best results when choosing a potential, you should do a thorough search of published literature and on-line databases such as the Interatomic Potentials Repository Project (NIST) or the Knowledgebase of Interatomic Models (KIM). Whatever potential you choose for your application, you should verify that you have defined it and are using it correctly in LAMMPS, by comparing with published results for that potential.

2nd IMPORTANT NOTE: The DATE field in the first line of each of these files is printed to the screen and log file when it is read by a LAMMPS input script. If an updated or corrected version of the same potential file is later added to the LAMMPS distribution, then a new DATE will be added to the file. This means you can "diff" an old and new log file and see that the potential file changed, which could affect your simulation results.

A small amount of metadata is included in the first line of each file in order to track the provenance of each file. The metadata is indicated by a keyword followed by white space, followed by the metadata, followed by whitespace. The metadata is intended to be straightforward and human-readable, while still conforming to a standard format.

DATE: Format is "yyyy-mm-dd". This indicates the date of a significant change to the file. Multiple entries can appear in reverse chronological order. As described above, the first of these will be printed to the screen and log file when it is read by a LAMMPS input script.

CONTRIBUTOR: Format is "name[, email address]". This indicates the person who contributed the file and/or who is best able to provide more details about its provenance.

CITATION: Format is "surname[[, surname] and surname], Publication abbreviation with spaces and no periods, volume, page[-page], (year)"

COMMENT: This one is optional and is used to hold any other text that can not go elsewhere.

If the first line of the file is always skipped by the file reader, then the first line should begin with the DATE keyword. If the file format supports comment lines, then the first line should be a comment line with the metadata e.g. "# DATE: 2010-01-01..." If the first line of the file is required to begin with data, then the metadata will be appended to the first line e.g. "7 DATE: 2010-01-01..."

The prefix of each file indicates the element(s) it is parameterized for. An additional lower-case identification tag may be appended.

Si = Silicon SiC = Silicon and Carbon Au_u3 = Gold universal 3

The suffix of each file indicates the pair style it is used with:

adp ADP angular dependent potential airebo AI-REBO and REBO potentials bop.table BOP potential, tabulated form cdeam concentration-dependent EAM comb COMB potential comb3 COMB3 potential eam embedded atom method (EAM) single element, DYNAMO funcfl format eam.alloy EAM multi-element alloy, DYNAMO setfl format eam.fs Finnis-Sinclair EAM format (single element or alloy) edip EDIP potential for silicon-based materials eim embedded-ion method (EIM) potential lcbop LCBOP long-range bond-order potential meam modified EAM (MEAM) library and individual elements/alloys meam.spline modified EAM (MEAM) spline potential meam.sw.spline modified EAM (MEAM) Stillinger-Weber spline potential nb3b.harmonic nonbonded 3-body harmonic potential poly polymorphic 3-body potential reax ReaxFF potential (see README.reax for more info) snap SNAP potential snapcoeff SNAP potential snapparam SNAP potential streitz Coulombic portion of Streitz-Mintmire potential sw Stillinger-Weber potential tersoff Tersoff potential tersoff.mod modified Tersoff potential tersoff.zbl Tersoff with ZBL core