6.2. Package details — LAMMPS documentation

\(\renewcommand{\AA}{\text{Å}}\)

# 6.2. Package details

Here is a brief description of all packages in LAMMPS. It lists authors (if applicable) and summarizes the package contents. It has specific instructions on how to install the package, including, if necessary, info on how to download or build any extra library it requires. It also gives links to documentation, example scripts, and pictures/movies (if available) that illustrate use of the package.

The majority of packages can be included in a LAMMPS build with a single setting (`-D PKG_<NAME>=on` for CMake) or command (`make yes-<name>` for make). See the Build package page for more info. A few packages may require additional steps; this is indicated in the descriptions below. The Build extras page gives those details.

Note

To see the complete list of commands a package adds to LAMMPS, you can examine the files in its src directory, e.g. “ls src/GRANULAR”. Files with names that start with fix, compute, atom, pair, bond, angle, etc correspond to commands with the same style name as contained in the file name.

ADIOS | AMOEBA | ASPHERE | ATC | AWPMD | BOCS
BODY | BPM | BROWNIAN | CG-DNA | CG-SPICA | CLASS2
COLLOID | COLVARS | COMPRESS | CORESHELL | DIELECTRIC | DIFFRACTION
DIPOLE | DPD-BASIC | DPD-MESO | DPD-REACT | DPD-SMOOTH | DRUDE
EFF | ELECTRODE | EXTRA-COMPUTE | EXTRA-DUMP | EXTRA-FIX | EXTRA-MOLECULE
EXTRA-PAIR | FEP | GPU | GRANULAR | H5MD | INTEL
INTERLAYER | KIM | KOKKOS | KSPACE | LATBOLTZ | LEPTON
MACHDYN | MANIFOLD | MANYBODY | MC | MDI | MEAM
MESONT | MGPT | MISC | ML-HDNNP | ML-IAP | ML-PACE
ML-POD | ML-QUIP | ML-RANN | ML-SNAP | MOFFF | MOLECULE
MOLFILE | MPIIO | MSCG | NETCDF | OPENMP | OPT
ORIENT | PERI | PHONON | PLUGIN | PLUMED | POEMS
PTM | PYTHON | QEQ | QMMM | QTB | REACTION
REAXFF | REPLICA | RIGID | SCAFACOS | SHOCK | SMTBQ
SPH | SPIN | SRD | TALLY | UEF | VORONOI
VTK | YAFF |  |  |  |

## 6.2.1. ADIOS package

Contents:

ADIOS is a high-performance I/O library. This package implements the dump atom/adios, dump custom/adios and read_dump … format adios commands to write and read data using the ADIOS library.

Authors: Norbert Podhorszki (ORNL) from the ADIOS developer team.

New in version 28Feb2019.

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/ADIOS: filenames -> commands

- src/ADIOS/README

- examples/PACKAGES/adios

- https://github.com/ornladios/ADIOS2

- dump atom/adios

- dump custom/adios

- read_dump

## 6.2.2. AMOEBA package

Contents:

Implementation of the AMOEBA and HIPPO polarized force fields originally developed by Jay Ponder’s group at the U Washington at St Louis. The LAMMPS implementation is based on Fortran 90 code provided by the Ponder group in their Tinker MD software.

Authors: Josh Rackers and Steve Plimpton (Sandia), Trung Nguyen (U

  Chicago)

Supporting info:

- src/AMOEBA: filenames -> commands

- AMOEBA and HIPPO howto

- pair_style amoeba

- pair_style hippo

- atom_style amoeba

- angle_style amoeba

- improper_style amoeba

- fix amoeba/bitorsion

- fix amoeba/pitorsion

- tools/tinker/tinker2lmp.py

- examples/amoeba

## 6.2.3. ASPHERE package

Contents:

Computes, time-integration fixes, and pair styles for aspherical particle models including ellipsoids, 2d lines, and 3d triangles.

Supporting info:

- src/ASPHERE: filenames -> commands

- Howto spherical

- pair_style gayberne

- pair_style resquared

- pair_style ylz

- doc/PDF/pair_gayberne_extra.pdf

- doc/PDF/pair_resquared_extra.pdf

- examples/ASPHERE

- examples/ellipse

- https://www.lammps.org/movies.html#line

- https://www.lammps.org/movies.html#tri

## 6.2.4. ATC package

Contents:

ATC stands for atoms-to-continuum. This package implements a fix atc command to either couple molecular dynamics with continuum finite element equations or perform on-the-fly conversion of atomic information to continuum fields.

Authors: Reese Jones, Jeremy Templeton, Jon Zimmerman (Sandia).

Install:

This package has specific installation instructions on the Build extras page. The ATC package requires that also the MANYBODY package is installed.

Supporting info:

- src/ATC: filenames -> commands

- src/ATC/README

- fix atc

- examples/PACKAGES/atc

- https://www.lammps.org/pictures.html#atc

## 6.2.5. AWPMD package

Contents:

AWPMD stands for Antisymmetrized Wave Packet Molecular Dynamics. This package implements an atom, pair, and fix style which allows electrons to be treated as explicit particles in a classical molecular dynamics model.

Author: Ilya Valuev (JIHT, Russia).

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/AWPMD: filenames -> commands

- src/AWPMD/README

- pair_style awpmd/cut

- examples/PACKAGES/awpmd

## 6.2.6. BOCS package

Contents:

This package provides fix bocs, a modified version of fix npt which includes the pressure correction to the barostat as outlined in:

N. J. H. Dunn and W. G. Noid, “Bottom-up coarse-grained models that accurately describe the structure, pressure, and compressibility of molecular liquids”, J. Chem. Phys. 143, 243148 (2015).

Authors: Nicholas J. H. Dunn and Michael R. DeLyser (The Pennsylvania State University)

Supporting info:

The BOCS package for LAMMPS is part of the BOCS software package: https://github.com/noid-group/BOCS

See the following reference for information about the entire package:

Dunn, NJH; Lebold, KM; DeLyser, MR; Rudzinski, JF; Noid, WG. “BOCS: Bottom-Up Open-Source Coarse-Graining Software.” J. Phys. Chem. B. 122, 13, 3363-3377 (2018).

Example inputs are in the examples/PACKAGES/bocs folder.

## 6.2.7. BODY package

Contents:

Body-style particles with internal structure. Computes, time-integration fixes, pair styles, as well as the body styles themselves. See the Howto body page for an overview.

Supporting info:

- src/BODY filenames -> commands

- Howto_body

- atom_style body

- fix nve/body

- pair_style body/nparticle

- examples/body

## 6.2.8. BPM package

Contents:

Pair styles, bond styles, fixes, and computes for bonded particle models for mesoscale simulations of solids and fracture. See the Howto bpm page for an overview.

Authors: Joel T. Clemmer (Sandia National Labs)

New in version 4May2022.

Supporting info:

- src/BPM filenames -> commands

- Howto_bpm

- atom_style bpm/sphere

- bond_style bpm/rotational

- bond_style bpm/spring

- compute nbond/atom

- fix nve/bpm/sphere

- pair_style bpm/spring

- examples/bpm

## 6.2.9. BROWNIAN package

Contents:

This package provides fix brownian, fix brownian/sphere, and fix brownian/asphere as well as fix propel/self which allow to do Brownian Dynamics time integration of point, spherical and aspherical particles and also support self-propelled particles.

Authors: Sam Cameron (University of Bristol), Stefan Paquay (while at Brandeis University) (initial version of fix propel/self)

New in version 14May2021.

Example inputs are in the examples/PACKAGES/brownian folder.

## 6.2.10. CG-DNA package

Contents:

Several pair styles, bond styles, and integration fixes for coarse-grained modelling of single- and double-stranded DNA and RNA based on the oxDNA and oxRNA model of Doye, Louis and Ouldridge. The package includes Langevin-type rigid-body integrators with improved stability.

Author: Oliver Henrich (University of Strathclyde, Glasgow).

Install:

The CG-DNA package requires that also the MOLECULE and ASPHERE packages are installed.

Supporting info:

- src/CG-DNA: filenames -> commands

- /src/CG-DNA/README

- pair_style oxdna/*

- pair_style oxdna2/*

- pair_style oxrna2/*

- bond_style oxdna/*

- bond_style oxdna2/*

- bond_style oxrna2/*

- fix nve/dotc/langevin

## 6.2.11. CG-SPICA package

Contents:

Several pair styles and an angle style which implement the coarse-grained SPICA (formerly called SDK) model which enables simulation of biological or soft material systems.

Original Author: Axel Kohlmeyer (Temple U).

Maintainers: Yusuke Miyazaki and Wataru Shinoda (Okayama U).

Supporting info:

- src/CG-SPICA: filenames -> commands

- src/CG-SPICA/README

- pair_style lj/spica/*

- angle_style spica

- examples/PACKAGES/cgspica

- https://www.lammps.org/pictures.html#cg

- https://www.spica-ff.org/

## 6.2.12. CLASS2 package

Contents:

Bond, angle, dihedral, improper, and pair styles for the COMPASS CLASS2 molecular force field.

Supporting info:

- src/CLASS2: filenames -> commands

- bond_style class2

- angle_style class2

- dihedral_style class2

- improper_style class2

- pair_style lj/class2

## 6.2.13. COLLOID package

Contents:

Coarse-grained finite-size colloidal particles. Pair styles and fix wall styles for colloidal interactions. Includes the Fast Lubrication Dynamics (FLD) method for hydrodynamic interactions, which is a simplified approximation to Stokesian dynamics.

Authors: This package includes Fast Lubrication Dynamics pair styles which were created by Amit Kumar and Michael Bybee from Jonathan Higdon’s group at UIUC.

Supporting info:

- src/COLLOID: filenames -> commands

- fix wall/colloid

- pair_style colloid

- pair_style yukawa/colloid

- pair_style brownian

- pair_style lubricate

- pair_style lubricateU

- examples/colloid

- examples/srd

## 6.2.14. COLVARS package

Contents:

Colvars stands for collective variables, which can be used to implement various enhanced sampling methods, including Adaptive Biasing Force, Metadynamics, Steered MD, Umbrella Sampling and Restraints. A fix colvars command is implemented which wraps a COLVARS library, which implements these methods. simulations.

Authors: The COLVARS library is written and maintained by Giacomo Fiorin (NIH, Bethesda, MD, USA) and Jerome Henin (CNRS, Paris, France), originally for the NAMD MD code, but with portability in mind. Axel Kohlmeyer (Temple U) provided the interface to LAMMPS.

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/COLVARS: filenames -> commands

- doc/PDF/colvars-refman-lammps.pdf

- src/COLVARS/README

- lib/colvars/README

- fix colvars

- group2ndx

- ndx2group

- examples/PACKAGES/colvars

## 6.2.15. COMPRESS package

Contents:

Compressed output of dump files via the zlib compression library, using dump styles with a “gz” in their style name.

To use this package you must have the zlib compression library available on your system.

Author: Axel Kohlmeyer (Temple U).

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/COMPRESS: filenames -> commands

- src/COMPRESS/README

- lib/compress/README

- dump atom/gz

- dump cfg/gz

- dump custom/gz

- dump xyz/gz

## 6.2.16. CORESHELL package

Contents:

Compute and pair styles that implement the adiabatic core/shell model for polarizability. The pair styles augment Born, Buckingham, and Lennard-Jones styles with core/shell capabilities. The compute temp/cs command calculates the temperature of a system with core/shell particles. See the Howto coreshell page for an overview of how to use this package.

Author: Hendrik Heenen (Technical U of Munich).

Supporting info:

- src/CORESHELL: filenames -> commands

- Howto coreshell

- Howto polarizable

- compute temp/cs

- pair_style born/coul/long/cs

- pair_style buck/coul/long/cs

- pair_style lj/cut/coul/long/cs

- examples/coreshell

## 6.2.17. DIELECTRIC package

Contents:

An atom style, multiple pair styles, several fixes, Kspace styles and a compute for simulating systems using boundary element solvers for computing the induced charges at the interface between two media with different dielectric constants.

Install:

To use this package, also the KSPACE and EXTRA-PAIR packages need to be installed.

Author: Trung Nguyen and Monica Olvera de la Cruz (Northwestern U)

New in version 2Jul2021.

Supporting info:

- src/DIELECTRIC: filenames -> commands

- atom_style dielectric

- pair_style coul/cut/dielectric

- pair_style coul/long/dielectric

- pair_style lj/cut/coul/cut/dielectric

- pair_style lj/cut/coul/debye/dielectric

- pair_style lj/cut/coul/long/dielectric

- pair_style lj/cut/coul/msm/dielectric

- pair_style pppm/dielectric

- pair_style pppm/disp/dielectric

- pair_style msm/dielectric

- fix_style polarize/bem/icc

- fix_style polarize/bem/gmres

- fix_style polarize/functional

- compute efield/atom

- examples/PACKAGES/dielectric

## 6.2.18. DIFFRACTION package

Contents:

Two computes and a fix for calculating x-ray and electron diffraction intensities based on kinematic diffraction theory.

Author: Shawn Coleman while at the U Arkansas.

Supporting info:

- src/DIFFRACTION: filenames -> commands

- compute saed

- compute xrd

- fix saed/vtk

- examples/PACKAGES/diffraction

## 6.2.19. DIPOLE package

Contents:

An atom style and several pair styles for point dipole models with short-range or long-range interactions.

Supporting info:

- src/DIPOLE: filenames -> commands

- atom_style dipole

- pair_style lj/cut/dipole/cut

- pair_style lj/cut/dipole/long

- pair_style lj/long/dipole/long

- angle_style dipole

- examples/dipole

## 6.2.20. DPD-BASIC package

Contents:

Pair styles for the basic dissipative particle dynamics (DPD) method and DPD thermostatting.

Author: Kurt Smith (U Pittsburgh), Martin Svoboda, Martin Lisal (ICPF and UJEP)

Supporting info:

- src/DPD-BASIC: filenames -> commands

- pair_style dpd

- pair_style dpd/tstat

- pair_style dpd/ext

- pair_style dpd/ext/tstat

- examples/PACKAGES/dpd-basic

## 6.2.21. DPD-MESO package

Contents:

Several extensions of the dissipative particle dynamics (DPD) method. Specifically, energy-conserving DPD (eDPD) that can model non-isothermal processes, many-body DPD (mDPD) for simulating vapor-liquid coexistence, and transport DPD (tDPD) for modeling advection-diffusion-reaction systems. The equations of motion of these DPD extensions are integrated through a modified velocity-Verlet (MVV) algorithm.

Author: Zhen Li (Department of Mechanical Engineering, Clemson University)

Supporting info:

- src/DPD-MESO: filenames -> commands

- src/DPD-MESO/README

- atom_style edpd

- pair_style edpd

- pair_style mdpd

- pair_style tdpd

- fix mvv/dpd

- examples/PACKAGES/mesodpd

- https://www.lammps.org/movies.html#mesodpd

## 6.2.22. DPD-REACT package

Contents:

DPD stands for dissipative particle dynamics. This package implements coarse-grained DPD-based models for energetic, reactive molecular crystalline materials. It includes many pair styles specific to these systems, including for reactive DPD, where each particle has internal state for multiple species and a coupled set of chemical reaction ODEs are integrated each timestep. Highly accurate time integrators for isothermal, isoenergetic, isobaric and isenthalpic conditions are included. These enable long timesteps via the Shardlow splitting algorithm.

Authors: Jim Larentzos (ARL), Tim Mattox (Engility Corp), and John Brennan (ARL).

Supporting info:

- src/DPD-REACT: filenames -> commands

- /src/DPD-REACT/README

- compute dpd

- compute dpd/atom

- fix eos/cv

- fix eos/table

- fix eos/table/rx

- fix shardlow

- fix rx

- pair_style table/rx

- pair_style dpd/fdt

- pair_style dpd/fdt/energy

- pair_style exp6/rx

- pair_style multi/lucy

- pair_style multi/lucy/rx

- examples/PACKAGES/dpd-react

## 6.2.23. DPD-SMOOTH package

Contents:

A pair style for smoothed dissipative particle dynamics (SDPD), which is an extension of smoothed particle hydrodynamics (SPH) to mesoscale where thermal fluctuations are important (see the SPH package). Also two fixes for moving and rigid body integration of SPH/SDPD particles (particles of atom_style meso).

Author: Morteza Jalalvand (Institute for Advanced Studies in Basic Sciences, Iran).

Supporting info:

- src/DPD-SMOOTH: filenames -> commands

- src/DPD-SMOOTH/README

- pair_style sdpd/taitwater/isothermal

- fix meso/move

- fix rigid/meso

- examples/PACKAGES/dpd-smooth

## 6.2.24. DRUDE package

Contents:

Fixes, pair styles, and a compute to simulate thermalized Drude oscillators as a model of polarization. See the Howto drude and Howto drude2 pages for an overview of how to use the package. There are auxiliary tools for using this package in tools/drude.

Authors: Alain Dequidt (U Clermont Auvergne), Julien Devemy (CNRS), and Agilio Padua (ENS de Lyon).

Supporting info:

- src/DRUDE: filenames -> commands

- Howto drude

- Howto drude2

- Howto polarizable

- src/DRUDE/README

- fix drude

- fix drude/transform/*

- compute temp/drude

- pair_style thole

- pair_style lj/cut/thole/long

- examples/PACKAGES/drude

- tools/drude

## 6.2.25. EFF package

Contents:

EFF stands for electron force field which allows a classical MD code to model electrons as particles of variable radius. This package contains atom, pair, fix and compute styles which implement the eFF as described in A. Jaramillo-Botero, J. Su, Q. An, and W.A. Goddard III, JCC, 2010. The eFF potential was first introduced by Su and Goddard, in 2007. There are auxiliary tools for using this package in tools/eff; see its README file.

Author: Andres Jaramillo-Botero (CalTech).

Supporting info:

- src/EFF: filenames -> commands

- src/EFF/README

- atom_style electron

- fix nve/eff

- fix nvt/eff

- fix npt/eff

- fix langevin/eff

- compute temp/eff

- pair_style eff/cut

- pair_style eff/inline

- examples/PACKAGES/eff

- tools/eff/README

- tools/eff

- https://www.lammps.org/movies.html#eff

## 6.2.26. ELECTRODE package

Contents:

The ELECTRODE package allows the user to enforce a constant potential method for groups of atoms that interact with the remaining atoms as electrolyte.

Authors: The ELECTRODE package is written and maintained by Ludwig Ahrens-Iwers (TUHH, Hamburg, Germany), Shern Tee (UQ, Brisbane, Australia) and Robert Meissner (TUHH, Hamburg, Germany).

New in version 4May2022.

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- fix electrode/conp

- fix electrode/conq

- fix electrode/thermo

## 6.2.27. EXTRA-COMPUTE package

Contents:

Additional compute styles that are less commonly used.

Supporting info:

- src/EXTRA-COMPUTE: filenames -> commands

- compute

## 6.2.28. EXTRA-DUMP package

Contents:

Additional dump styles that are less commonly used.

Supporting info:

- src/EXTRA-DUMP: filenames -> commands

- dump

## 6.2.29. EXTRA-FIX package

Contents:

Additional fix styles that are less commonly used.

Supporting info:

- src/EXTRA-FIX: filenames -> commands

- fix

## 6.2.30. EXTRA-MOLECULE package

Contents:

Additional bond, angle, dihedral, and improper styles that are less commonly used.

Install:

To use this package, also the MOLECULE package needs to be installed.

Supporting info:

- src/EXTRA-MOLECULE: filenames -> commands

- molecular styles

## 6.2.31. EXTRA-PAIR package

Contents:

Additional pair styles that are less commonly used.

Supporting info:

- src/EXTRA-PAIR: filenames -> commands

- pair_style

## 6.2.32. FEP package

Contents:

FEP stands for free energy perturbation. This package provides methods for performing FEP simulations by using a fix adapt/fep command with soft-core pair potentials, which have a “soft” in their style name. There are auxiliary tools for using this package in tools/fep; see its README file.

Author: Agilio Padua (ENS de Lyon)

Supporting info:

- src/FEP: filenames -> commands

- src/FEP/README

- fix adapt/fep

- compute fep

- pair_style */soft

- examples/PACKAGES/fep

- tools/fep/README

- tools/fep

## 6.2.33. GPU package

Contents:

Dozens of pair styles and a version of the PPPM long-range Coulombic solver optimized for GPUs. All such styles have a “gpu” as a suffix in their style name. The GPU code can be compiled with either CUDA or OpenCL, however the OpenCL variants are no longer actively maintained and only the CUDA versions are regularly tested. The GPU package page gives details of what hardware and GPU software is required on your system, and details on how to build and use this package. Its styles can be invoked at run time via the “-sf gpu” or “-suffix gpu” command-line switches. See also the KOKKOS package, which has GPU-enabled styles.

Authors: Mike Brown (Intel) while at Sandia and ORNL and Trung Nguyen (Northwestern U) while at ORNL and later. AMD HIP support by Evgeny Kuznetsov, Vladimir Stegailov, and Vsevolod Nikolskiy (HSE University).

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/GPU: filenames -> commands

- src/GPU/README

- lib/gpu/README

- Accelerator packages

- GPU package

- Section 2.6 -sf gpu

- Section 2.6 -pk gpu

- package gpu

- Commands pages (pair, kspace) for styles followed by (g)

- Benchmarks page of website

## 6.2.34. GRANULAR package

Contents:

Pair styles and fixes for finite-size granular particles, which interact with each other and boundaries via frictional and dissipative potentials.

Supporting info:

- src/GRANULAR: filenames -> commands

- Howto granular

- fix pour

- fix wall/gran

- pair_style gran/hooke

- pair_style gran/hertz/history

- examples/granregion

- examples/pour

- bench/in.chute

- https://www.lammps.org/pictures.html#jamming

- https://www.lammps.org/movies.html#hopper

- https://www.lammps.org/movies.html#dem

- https://www.lammps.org/movies.html#brazil

- https://www.lammps.org/movies.html#granregion

## 6.2.35. H5MD package

Contents:

H5MD stands for HDF5 for MD. HDF5 is a portable, binary, self-describing file format, used by many scientific simulations. H5MD is a format for molecular simulations, built on top of HDF5. This package implements a dump h5md command to output LAMMPS snapshots in this format.

To use this package you must have the HDF5 library available on your system.

Author: Pierre de Buyl (KU Leuven) created both the package and the H5MD format.

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/H5MD: filenames -> commands

- src/H5MD/README

- lib/h5md/README

- dump h5md

## 6.2.36. INTEL package

Contents:

Dozens of pair, fix, bond, angle, dihedral, improper, and kspace styles which are optimized for Intel CPUs and KNLs (Knights Landing). All of them have an “intel” in their style name. The INTEL package page gives details of what hardware and compilers are required on your system, and how to build and use this package. Its styles can be invoked at run time via the “-sf intel” or “-suffix intel” command-line switches. Also see the KOKKOS, OPT, and OPENMP packages, which have styles optimized for CPUs and KNLs.

You need to have an Intel compiler, version 14 or higher to take full advantage of this package. While compilation with GNU compilers is supported, performance will be sub-optimal.

Note

the INTEL package contains styles that require using the -restrict flag, when compiling with Intel compilers.

Author: Mike Brown (Intel).

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/INTEL: filenames -> commands

- src/INTEL/README

- Accelerator packages

- INTEL package

- Section 2.6 -sf intel

- Section 2.6 -pk intel

- package intel

- Search the commands pages (fix, compute, pair, bond, angle, dihedral, improper, kspace) for styles followed by (i)

- src/INTEL/TEST

- Benchmarks page of website

## 6.2.37. INTERLAYER package

Contents:

A collection of pair styles specifically to be used for modeling layered materials, most commonly graphene sheets (or equivalents).

Supporting info:

- src/INTERLAYER: filenames -> commands

- Pair style page

- examples/PACKAGES/interlayer

## 6.2.38. KIM package

Contents:

This package contains a command with a set of sub-commands that serve as a wrapper on the Open Knowledgebase of Interatomic Models (OpenKIM) repository of interatomic models (IMs) enabling compatible ones to be used in LAMMPS simulations.

This includes kim init, and kim interactions commands to select, initialize and instantiate the IM, a kim query command to perform web queries for material property predictions of OpenKIM IMs, a kim param command to access KIM Model Parameters from LAMMPS, and a kim property command to write material properties computed in LAMMPS to standard KIM property instance format.

Support for KIM IMs that conform to the KIM Application Programming Interface (API) is provided by the pair_style kim command.

Note

The command pair_style kim is called by kim interactions and is not recommended to be directly used in input scripts.

To use this package you must have the KIM API library available on your system. The KIM API is available for download on the OpenKIM website. When installing LAMMPS from binary, the kim-api package is a dependency that is automatically downloaded and installed.

Information about the KIM project can be found at its website: https://openkim.org. The KIM project is led by Ellad Tadmor and Ryan Elliott (U Minnesota) and is funded by the National Science Foundation.

Authors: Ryan Elliott (U Minnesota) is the main developer for the KIM API and the pair_style kim command. Yaser Afshar (U Minnesota), Axel Kohlmeyer (Temple U), Ellad Tadmor (U Minnesota), and Daniel Karls (U Minnesota) contributed to the kim command interface in close collaboration with Ryan Elliott.

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- kim command

- pair_style kim

- src/KIM: filenames -> commands

- src/KIM/README

- lib/kim/README

- examples/kim

## 6.2.39. KOKKOS package

Contents:

Dozens of atom, pair, bond, angle, dihedral, improper, fix, compute styles adapted to compile using the Kokkos library which can convert them to OpenMP or CUDA code so that they run efficiently on multicore CPUs, KNLs, or GPUs. All the styles have a “kk” as a suffix in their style name. The KOKKOS package page gives details of what hardware and software is required on your system, and how to build and use this package. Its styles can be invoked at run time via the “-sf kk” or “-suffix kk” command-line switches. Also see the GPU, OPT, INTEL, and OPENMP packages, which have styles optimized for CPUs, KNLs, and GPUs.

You must have a C++14 compatible compiler to use this package. KOKKOS makes extensive use of advanced C++ features, which can expose compiler bugs, especially when compiling for maximum performance at high optimization levels. Please see the file lib/kokkos/README for a list of compilers and their respective platforms, that are known to work.

Authors: The KOKKOS package was created primarily by Christian Trott and Stan Moore (Sandia), with contributions from other folks as well. It uses the open-source Kokkos library which was developed by Carter Edwards, Christian Trott, and others at Sandia, and which is included in the LAMMPS distribution in lib/kokkos.

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/KOKKOS: filenames -> commands

- src/KOKKOS/README

- lib/kokkos/README

- Accelerator packages

- KOKKOS package

- Section 2.6 -k on …

- Section 2.6 -sf kk

- Section 2.6 -pk kokkos

- package kokkos

- Search the commands pages (fix, compute, pair, bond, angle, dihedral, improper, kspace) for styles followed by (k)

- Benchmarks page of website

## 6.2.40. KSPACE package

Contents:

A variety of long-range Coulombic solvers, as well as pair styles which compute the corresponding short-range pairwise Coulombic interactions. These include Ewald, particle-particle particle-mesh (PPPM), and multilevel summation method (MSM) solvers.

Install:

Building with this package requires a 1d FFT library be present on your system for use by the PPPM solvers. This can be the KISS FFT library provided with LAMMPS, third party libraries like FFTW, or a vendor-supplied FFT library. See the Build settings page for details on how to select different FFT options for your LAMPMS build.

Supporting info:

- src/KSPACE: filenames -> commands

- kspace_style

- doc/PDF/kspace.pdf

- Howto tip3p

- Howto tip4p

- Howto spc

- pair_style coul

- Search the pair style page for styles with “long” or “msm” in name

- examples/peptide

- bench/in.rhodo

## 6.2.41. LATBOLTZ package

Contents:

Fixes which implement a background Lattice-Boltzmann (LB) fluid, which can be used to model MD particles influenced by hydrodynamic forces.

Authors: Frances Mackay and Colin Denniston (University of Western Ontario).

Install:

The LATBOLTZ package requires that LAMMPS is build in MPI parallel mode.

Supporting info:

- src/LATBOLTZ: filenames -> commands

- src/LATBOLTZ/README

- fix lb/fluid

- fix lb/momentum

- fix lb/viscous

- examples/PACKAGES/latboltz

## 6.2.42. LEPTON package

Contents:

Styles for pair, bond, and angle forces that evaluate the potential function from a string using the Lepton mathematical expression parser. Lepton is a C++ library that is bundled with OpenMM and can be used for parsing, evaluating, differentiating, and analyzing mathematical expressions. This is a more lightweight and efficient alternative for evaluating custom potential function to an embedded Python interpreter as used in the PYTHON package. On the other hand, since the potentials are evaluated form analytical expressions, they are more precise than what can be done with tabulated potentials.

Authors: Axel Kohlmeyer (Temple U). Lepton itself is developed by Peter Eastman at Stanford University.

New in version 8Feb2023.

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/LEPTON: filenames -> commands

- lib/lepton/README.md

- pair_style lepton

- bond_style lepton

- angle_style lepton

- dihedral_style lepton

## 6.2.43. MACHDYN package

Contents:

An atom style, fixes, computes, and several pair styles which implements smoothed Mach dynamics (SMD) for solids, which is a model related to smoothed particle hydrodynamics (SPH) for liquids (see the SPH package).

This package solves solids mechanics problems via a state of the art stabilized meshless method with hourglass control. It can specify hydrostatic interactions independently from material strength models, i.e. pressure and deviatoric stresses are separated. It provides many material models (Johnson-Cook, plasticity with hardening, Mie-Grueneisen, Polynomial EOS) and allows new material models to be added. It implements rigid boundary conditions (walls) which can be specified as surface geometries from *.STL files.

Author: Georg Ganzenmuller (Fraunhofer-Institute for High-Speed Dynamics, Ernst Mach Institute, Germany).

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/MACHDYN: filenames -> commands

- src/MACHDYN/README

- doc/PDF/MACHDYN_LAMMPS_userguide.pdf

- examples/PACKAGES/machdyn

- https://www.lammps.org/movies.html#smd

## 6.2.44. MANIFOLD package

Contents:

Several fixes and a “manifold” class which enable simulations of particles constrained to a manifold (a 2D surface within the 3D simulation box). This is done by applying the RATTLE constraint algorithm to formulate single-particle constraint functions g(xi,yi,zi) = 0 and their derivative (i.e. the normal of the manifold) n = grad(g).

Author: Stefan Paquay (until 2017: Eindhoven University of Technology (TU/e), The Netherlands; since 2017: Brandeis University, Waltham, MA, USA)

Supporting info:

- src/MANIFOLD: filenames -> commands

- src/MANIFOLD/README

- Howto manifold

- fix manifoldforce

- fix nve/manifold/rattle

- fix nvt/manifold/rattle

- examples/PACKAGES/manifold

- https://www.lammps.org/movies.html#manifold

## 6.2.45. MANYBODY package

Contents:

A variety of many-body and bond-order potentials. These include (AI)REBO, BOP, EAM, EIM, Stillinger-Weber, and Tersoff potentials.

Supporting info:

- src/MANYBODY: filenames -> commands

- Pair style page

- examples/comb

- examples/eim

- examples/nb3d

- examples/shear

- examples/streitz

- examples/vashishta

- bench/in.eam

## 6.2.46. MC package

Contents:

Several fixes and a pair style that have Monte Carlo (MC) or MC-like attributes. These include fixes for creating, breaking, and swapping bonds, for performing atomic swaps, and performing grand canonical MC (GCMC), semi-grand canonical MC (SGCMC), or similar processes in conjunction with molecular dynamics (MD).

Supporting info:

- src/MC: filenames -> commands

- fix atom/swap

- fix bond/break

- fix bond/create

- fix bond/create/angle

- fix bond/swap

- fix charge/regulation

- fix gcmc

- fix sgcmc

- fix tfmc

- fix widom

- pair_style dsmc

- https://www.lammps.org/movies.html#gcmc

## 6.2.47. MDI package

Contents:

A LAMMPS command and fixes to allow client-server coupling of LAMMPS to other atomic or molecular simulation codes or materials modeling workflows via the MolSSI Driver Interface (MDI) library.

Author: Taylor Barnes - MolSSI, taylor.a.barnes at gmail.com

New in version 14May2021.

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/MDI/README

- lib/mdi/README

- Howto MDI

- mdi

- fix mdi/qm

- examples/PACKAGES/mdi

## 6.2.48. MEAM package

Contents:

A pair style for the modified embedded atom (MEAM) potential translated from the Fortran version in the (obsolete) MEAM package to plain C++. The MEAM fully replaces the MEAM package, which has been removed from LAMMPS after the 12 December 2018 version.

Author: Sebastian Huetter, (Otto-von-Guericke University Magdeburg) based on the Fortran version of Greg Wagner (Northwestern U) while at Sandia.

Supporting info:

- src/MEAM: filenames -> commands

- src/MEAM/README

- pair_style meam

- examples/meam

## 6.2.49. MESONT package

Contents:

MESONT is a LAMMPS package for simulation of nanomechanics of nanotubes (NTs). The model is based on a coarse-grained representation of NTs as “flexible cylinders” consisting of a variable number of segments. Internal interactions within a NT and the van der Waals interaction between the tubes are described by a mesoscopic force field designed and parameterized based on the results of atomic-level molecular dynamics simulations. The description of the force field is provided in the papers listed in `src/MESONT/README`.

This package used to have two independent implementations of this model: the original implementation using a Fortran library written by the developers of the model and a second implementation written in C++ by Philipp Kloza (U Cambridge). Since the C++ implementation offers the same features as the original implementation with the addition of friction, is typically faster, and easier to compile/install, the Fortran library based implementation has since been obsoleted and removed from the distribution. You have to download and compile an older version of LAMMPS if you want to use those.

Download of potential files:

The potential files for these pair styles are very large and thus are not included in the regular downloaded packages of LAMMPS or the git repositories. Instead, they will be automatically downloaded from a web server when the package is installed for the first time.

Authors of the obsoleted *mesont* styles:

Maxim V. Shugaev (University of Virginia), Alexey N. Volkov (University of Alabama), Leonid V. Zhigilei (University of Virginia)

Deprecated since version 8Feb2023.

Author of the C++ styles: Philipp Kloza (U Cambridge)

New in version 15Jun2020.

Supporting info:

- src/MESONT: filenames -> commands

- src/MESONT/README

- bond_style mesocnt

- angle_style mesocnt

- pair_style mesocnt

- examples/PACKAGES/mesont

## 6.2.50. MGPT package

Contents:

A pair style which provides a fast implementation of the quantum-based MGPT multi-ion potentials. The MGPT or model GPT method derives from first-principles DFT-based generalized pseudopotential theory (GPT) through a series of systematic approximations valid for mid-period transition metals with nearly half-filled d bands. The MGPT method was originally developed by John Moriarty at LLNL. The pair style in this package calculates forces and energies using an optimized matrix-MGPT algorithm due to Tomas Oppelstrup at LLNL.

Authors: Tomas Oppelstrup and John Moriarty (LLNL).

Supporting info:

- src/MGPT: filenames -> commands

- src/MGPT/README

- pair_style mgpt

- examples/PACKAGES/mgpt

## 6.2.51. MISC package

Contents:

A variety of compute, fix, pair, bond styles with specialized capabilities that don’t align with other packages. Do a directory listing, “ls src/MISC”, to see the list of commands.

Note

the MISC package contains styles that require using the -restrict flag, when compiling with Intel compilers.

Supporting info:

- src/MISC: filenames -> commands

- bond_style special

- compute viscosity/cos

- fix accelerate/cos

- fix imd

- fix ipi

- pair_style agni

- pair_style list

- pair_style srp

- pair_style tracker

## 6.2.52. ML-HDNNP package

Contents:

A pair_style hdnnp command which allows to use high-dimensional neural network potentials (HDNNPs), a form of machine learning potentials. HDNNPs must be carefully trained prior to their application in a molecular dynamics simulation.

To use this package you must have the n2p2 library installed and compiled on your system.

Author: Andreas Singraber

New in version 27May2021.

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/ML-HDNNP: filenames -> commands

- src/ML-HDNNP/README

- lib/hdnnp/README

- pair_style hdnnp

- examples/PACKAGES/hdnnp

## 6.2.53. ML-IAP package

Contents:

A general interface for machine-learning interatomic potentials, including PyTorch.

Install:

To use this package, also the ML-SNAP package needs to be installed. To make the mliappy model available, also the PYTHON package needs to be installed, the version of Python must be 3.6 or later, and the cython software must be installed.

Author: Aidan Thompson (Sandia), Nicholas Lubbers (LANL).

New in version 30Jun2020.

Supporting info:

- src/ML-IAP: filenames -> commands

- src/ML-IAP/README.md

- pair_style mliap

- compute_style mliap

- examples/mliap (see README)

When built with the mliappy model this package includes an extension for coupling with Python models, including PyTorch. In this case, the Python interpreter linked to LAMMPS will need the `cython` and `numpy` modules installed. The provided examples build models with PyTorch, which would therefore also needs to be installed to run those examples.

## 6.2.54. ML-PACE package

Contents:

A pair style for the Atomic Cluster Expansion potential (ACE). ACE is a methodology for deriving a highly accurate classical potential fit to a large archive of quantum mechanical (DFT) data. The ML-PACE package provides an efficient implementation for running simulations with ACE potentials.

Authors:

This package was written by Yury Lysogorskiy^1, Cas van der Oord^2, Anton Bochkarev^1, Sarath Menon^1, Matteo Rinaldi^1, Thomas Hammerschmidt^1, Matous Mrovec^1, Aidan Thompson^3, Gabor Csanyi^2, Christoph Ortner^4, Ralf Drautz^1.

> ^1: Ruhr-University Bochum, Bochum, Germany

> ^2: University of Cambridge, Cambridge, United Kingdom

> ^3: Sandia National Laboratories, Albuquerque, New Mexico, USA

> ^4: University of British Columbia, Vancouver, BC, Canada

New in version 14May2021.

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/ML-PACE: filenames -> commands

- pair_style pace

- examples/PACKAGES/pace

## 6.2.55. ML-POD package

Contents:

A pair style and fitpod style for Proper Orthogonal Descriptors (POD). POD is a methodology for deriving descriptors based on the proper orthogonal decomposition. The ML-POD package provides an efficient implementation for running simulations with POD potentials, along with fitting the potentials natively in LAMMPS.

Authors:

Ngoc Cuong Nguyen (MIT), Andrew Rohskopf (Sandia)

New in version 22Dec2022.

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/ML-POD: filenames -> commands

- pair_style pod

- command_style fitpod

- examples/PACKAGES/pod

## 6.2.56. ML-QUIP package

Contents:

A pair_style quip command which wraps the QUIP libAtoms library, which includes a variety of interatomic potentials, including Gaussian Approximation Potential (GAP) models developed by the Cambridge University group.

To use this package you must have the QUIP libAtoms library available on your system.

Author: Albert Bartok (Cambridge University)

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/ML-QUIP: filenames -> commands

- src/ML-QUIP/README

- pair_style quip

- examples/PACKAGES/quip

## 6.2.57. ML-RANN package

Contents:

A pair style for using rapid atomistic neural network (RANN) potentials. These neural network potentials work by first generating a series of symmetry functions from the neighbor list and then using these values as the input layer of a neural network.

Authors:

This package was written by Christopher Barrett with contributions by Doyl Dickel, Mississippi State University.

New in version 27May2021.

Supporting info:

- src/ML-RANN: filenames -> commands

- pair_style rann

- examples/PACKAGES/rann

## 6.2.58. ML-SNAP package

Contents:

A pair style for the spectral neighbor analysis potential (SNAP). SNAP is methodology for deriving a highly accurate classical potential fit to a large archive of quantum mechanical (DFT) data. Also several computes which analyze attributes of the potential.

Author: Aidan Thompson (Sandia).

Supporting info:

- src/ML-SNAP: filenames -> commands

- pair_style snap

- compute sna/atom

- compute sna/grid

- compute sna/grid/local

- compute snad/atom

- compute snav/atom

- examples/snap

## 6.2.59. MOFFF package

Contents:

Pair, angle and improper styles needed to employ the MOF-FF force field by Schmid and coworkers with LAMMPS. MOF-FF is a first principles derived force field with the primary aim to simulate MOFs and related porous framework materials, using spherical Gaussian charges. It is described in S. Bureekaew et al., Phys. Stat. Sol. B 2013, 250, 1128-1141. For the usage of MOF-FF see the example in the example directory as well as the MOF+ website.

Author: Hendrik Heenen (Technical U of Munich), Rochus Schmid (Ruhr-University Bochum).

Supporting info:

- src/MOFFF: filenames -> commands

- src/MOFFF/README

- pair_style buck6d/coul/gauss

- angle_style class2

- angle_style cosine/buck6d

- improper_style inversion/harmonic

- examples/PACKAGES/mofff

## 6.2.60. MOLECULE package

Contents:

A large number of atom, pair, bond, angle, dihedral, improper styles that are used to model molecular systems with fixed covalent bonds. The pair styles include the Dreiding (hydrogen-bonding) and CHARMM force fields, and a TIP4P water model.

Supporting info:

- src/MOLECULE: filenames -> commands

- atom_style

- bond_style

- angle_style

- dihedral_style

- improper_style

- pair_style hbond/dreiding/lj

- pair_style lj/charmm/coul/charmm

- Howto bioFF

- examples/cmap

- examples/dreiding

- examples/micelle,

- examples/peptide

- bench/in.chain

- bench/in.rhodo

## 6.2.61. MOLFILE package

Contents:

A dump molfile command which uses molfile plugins that are bundled with the VMD molecular visualization and analysis program, to enable LAMMPS to dump snapshots in formats compatible with various molecular simulation tools.

To use this package you must have the desired VMD plugins available on your system.

Note that this package only provides the interface code, not the plugins themselves, which will be accessed when requesting a specific plugin via the dump molfile command. Plugins can be obtained from a VMD installation which has to match the platform that you are using to compile LAMMPS for. By adding plugins to VMD, support for new file formats can be added to LAMMPS (or VMD or other programs that use them) without having to re-compile the application itself. More information about the VMD molfile plugins can be found at https://www.ks.uiuc.edu/Research/vmd/plugins/molfile.

Author: Axel Kohlmeyer (Temple U).

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/MOLFILE: filenames -> commands

- src/MOLFILE/README

- lib/molfile/README

- dump molfile

## 6.2.62. MPIIO package

Contents:

Support for parallel output/input of dump and restart files via the MPIIO library. It adds dump styles with a “mpiio” in their style name. Restart files with an “.mpiio” suffix are also written and read in parallel.

Warning

The MPIIO package is currently unmaintained and has become unreliable. Use with caution.

Install:

The MPIIO package requires that LAMMPS is build in MPI parallel mode.

Supporting info:

- src/MPIIO: filenames -> commands

- dump

- restart

- write_restart

- read_restart

## 6.2.63. MSCG package

Contents:

A fix mscg command which can parameterize a Multi-Scale Coarse-Graining (MSCG) model using the open-source MS-CG library.

To use this package you must have the MS-CG library available on your system.

Authors: The fix was written by Lauren Abbott (Sandia). The MS-CG library was developed by Jacob Wagner in Greg Voth’s group at the University of Chicago.

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/MSCG: filenames -> commands

- src/MSCG/README

- lib/mscg/README

- examples/mscg

## 6.2.64. NETCDF package

Contents:

Dump styles for writing NetCDF formatted dump files. NetCDF is a portable, binary, self-describing file format developed on top of HDF5. The file contents follow the AMBER NetCDF trajectory conventions (https://ambermd.org/netcdf/nctraj.xhtml), but include extensions.

To use this package you must have the NetCDF library available on your system.

Note that NetCDF files can be directly visualized with the following tools:

- Ovito (Ovito supports the AMBER convention and the extensions mentioned above)

- VMD

Author: Lars Pastewka (Karlsruhe Institute of Technology).

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/NETCDF: filenames -> commands

- src/NETCDF/README

- lib/netcdf/README

- dump netcdf

## 6.2.65. OPENMP package

Contents:

Hundreds of pair, fix, compute, bond, angle, dihedral, improper, and kspace styles which are altered to enable threading on many-core CPUs via OpenMP directives. All of them have an “omp” in their style name. The OPENMP package page gives details of what hardware and compilers are required on your system, and how to build and use this package. Its styles can be invoked at run time via the “-sf omp” or “-suffix omp” command-line switches. Also see the KOKKOS, OPT, and INTEL packages, which have styles optimized for CPUs.

Author: Axel Kohlmeyer (Temple U).

Note

To enable multi-threading support the compile flag “-fopenmp” and the link flag “-fopenmp” (for GNU compilers, you have to look up the equivalent flags for other compilers) must be used to build LAMMPS. When using Intel compilers, also the “-restrict” flag is required. The OPENMP package can be compiled without enabling OpenMP; then all code will be compiled as serial and the only improvement over the regular styles are some data access optimization. These flags should be added to the CCFLAGS and LINKFLAGS lines of your Makefile.machine. See src/MAKE/OPTIONS/Makefile.omp for an example.

Once you have an appropriate Makefile.machine, you can install/uninstall the package and build LAMMPS in the usual manner:

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/OPENMP: filenames -> commands

- src/OPENMP/README

- Accelerator packages

- OPENMP package

- Command line option -suffix/-sf omp

- Command line option -package/-pk omp

- package omp

- Search the commands pages (fix, compute, pair, bond, angle, dihedral, improper, kspace) for styles followed by (o)

- Benchmarks page of website

## 6.2.66. OPT package

Contents:

A handful of pair styles which are optimized for improved CPU performance on single or multiple cores. These include EAM, LJ, CHARMM, and Morse potentials. The styles have an “opt” suffix in their style name. The OPT package page gives details of how to build and use this package. Its styles can be invoked at run time via the “-sf opt” or “-suffix opt” command-line switches. See also the KOKKOS, INTEL, and OPENMP packages, which have styles optimized for CPU performance.

Authors: James Fischer (High Performance Technologies), David Richie, and Vincent Natoli (Stone Ridge Technology).

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/OPT: filenames -> commands

- Accelerator packages

- OPT package

- Section 2.6 -sf opt

- Search the pair style page for styles followed by (t)

- Benchmarks page of website

## 6.2.67. ORIENT package

Contents:

A few fixes that apply orientation dependent forces for studying grain boundary migration.

Supporting info:

- src/ORIENT: filenames -> commands

- fix orient/bcc

- fix orient/fcc

- fix orient/eco

## 6.2.68. PERI package

Contents:

An atom style, several pair styles which implement different Peridynamics materials models, and several computes which calculate diagnostics. Peridynamics is a particle-based meshless continuum model.

Authors: The original package was created by Mike Parks (Sandia). Additional Peridynamics models were added by Rezwanur Rahman and John Foster (UTSA).

Supporting info:

- src/PERI: filenames -> commands

- Peridynamics Howto

- doc/PDF/PDLammps_overview.pdf

- doc/PDF/PDLammps_EPS.pdf

- doc/PDF/PDLammps_VES.pdf

- atom_style peri

- pair_style peri/*

- compute damage/atom

- compute plasticity/atom

- examples/peri

- https://www.lammps.org/movies.html#peri

## 6.2.69. PHONON package

Contents:

A fix phonon command that calculates dynamical matrices, which can then be used to compute phonon dispersion relations, directly from molecular dynamics simulations. And a dynamical_matrix as well as a third_order command to compute the dynamical matrix and third order tensor from finite differences.

Install:

The PHONON package requires that also the KSPACE package is installed.

Authors: Ling-Ti Kong (Shanghai Jiao Tong University) for “fix phonon” and Charlie Sievers (UC Davis) for “dynamical_matrix” and “third_order”

Supporting info:

- src/PHONON: filenames -> commands

- src/PHONON/README

- fix phonon

- dynamical_matrix

- third_order

- examples/PACKAGES/phonon

## 6.2.70. PLUGIN package

Contents:

A plugin command that can load and unload several kind of styles in LAMMPS from shared object files at runtime without having to recompile and relink LAMMPS.

When the environment variable `LAMMPS_PLUGIN_PATH` is set, then LAMMPS will search the directory (or directories) listed in this path for files with names that end in `plugin.so` (e.g. `helloplugin.so`) and will try to load the contained plugins automatically at start-up.

Authors: Axel Kohlmeyer (Temple U)

New in version 8Apr2021.

Supporting info:

- src/PLUGIN: filenames -> commands

- plugin command

- Information on writing plugins

- examples/plugin

## 6.2.71. PLUMED package

Contents:

The fix plumed command allows you to use the PLUMED free energy plugin for molecular dynamics to analyze and bias your LAMMPS trajectory on the fly. The PLUMED library is called from within the LAMMPS input script by using the fix plumed command.

Authors: The PLUMED library is written and maintained by Massimilliano Bonomi, Giovanni Bussi, Carlo Camiloni, and Gareth Tribello.

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/PLUMED/README

- lib/plumed/README

- fix plumed

- examples/PACKAGES/plumed

## 6.2.72. POEMS package

Contents:

A fix that wraps the Parallelizable Open source Efficient Multibody Software (POEMS) library, which is able to simulate the dynamics of articulated body systems. These are systems with multiple rigid bodies (collections of particles) whose motion is coupled by connections at hinge points.

Author: Rudra Mukherjee (JPL) while at RPI.

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/POEMS: filenames -> commands

- src/POEMS/README

- lib/poems/README

- fix poems

- examples/rigid

## 6.2.73. PTM package

Contents:

A compute ptm/atom command that calculates local structure characterization using the Polyhedral Template Matching methodology.

Author: Peter Mahler Larsen (MIT).

Supporting info:

- src/PTM: filenames not starting with ptm_ -> commands

- src/PTM: filenames starting with ptm_ -> supporting code

- src/PTM/LICENSE

- compute ptm/atom

## 6.2.74. PYTHON package

Contents:

A python command which allow you to execute Python code from a LAMMPS input script. The code can be in a separate file or embedded in the input script itself. See the Python call page for an overview of using Python from LAMMPS in this manner and all the Python manual pages for other ways to use LAMMPS and Python together.

Note

Building with the PYTHON package assumes you have a Python development environment (headers and libraries) available on your system, which needs to be either Python version 2.7 or Python 3.5 and later.

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/PYTHON: filenames -> commands

- Python call

- lib/python/README

- examples/python

## 6.2.75. QEQ package

Contents:

Several fixes for performing charge equilibration (QEq) via different algorithms. These can be used with pair styles that perform QEq as part of their formulation.

Supporting info:

- src/QEQ: filenames -> commands

- fix qeq/*

- examples/qeq

- examples/streitz

## 6.2.76. QMMM package

Contents:

A fix qmmm command which allows LAMMPS to be used as the MM code in a QM/MM simulation. This is currently only available in combination with the Quantum ESPRESSO package.

To use this package you must have Quantum ESPRESSO (QE) available on your system and include its coupling library in the compilation and then compile LAMMPS as a library. For QM/MM calculations you then build a custom binary with MPI support, that sets up 3 partitions with MPI sub-communicators (for inter- and intra-partition communication) and then calls the corresponding library interfaces on each partition (2x LAMMPS and 1x QE).

The current implementation supports an ONIOM style mechanical coupling and a multi-pole based electrostatic coupling to the Quantum ESPRESSO plane wave DFT package. The QM/MM interface has been written in a manner that coupling to other QM codes should be possible without changes to LAMMPS itself.

Authors: Axel Kohlmeyer (Temple U). Mariella Ippolito and Carlo Cavazzoni (CINECA, Italy)

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/QMMM: filenames -> commands

- src/QMMM/README

- lib/qmmm/README

- fix phonon

- lib/qmmm/example-ec/README

- lib/qmmm/example-mc/README

## 6.2.77. QTB package

Contents:

Two fixes which provide a self-consistent quantum treatment of vibrational modes in a classical molecular dynamics simulation. By coupling the MD simulation to a colored thermostat, it introduces zero point energy into the system, altering the energy power spectrum and the heat capacity to account for their quantum nature. This is useful when modeling systems at temperatures lower than their classical limits or when temperatures ramp across the classical limits in a simulation.

Author: Yuan Shen (Stanford U).

Supporting info:

- src/QTB: filenames -> commands

- src/QTB/README

- fix qtb

- fix qbmsst

- examples/PACKAGES/qtb

## 6.2.78. REACTION package

Contents:

This package implements the REACTER protocol, which allows for complex bond topology changes (reactions) during a running MD simulation when using classical force fields. Topology changes are defined in pre- and post-reaction molecule templates and can include creation and deletion of bonds, angles, dihedrals, impropers, atom types, bond types, angle types, dihedral types, improper types, and/or atomic charges. Other options currently available include reaction constraints (e.g., angle and Arrhenius constraints), deletion of reaction byproducts or other small molecules, creation of new atoms or molecules bonded to existing atoms, and using LAMMPS variables for input parameters.

Author: Jacob R. Gissinger (NASA Langley Research Center).

Supporting info:

- src/REACTION: filenames -> commands

- src/REACTION/README

- fix bond/react

- examples/PACKAGES/reaction

- 2017 LAMMPS Workshop

- 2019 LAMMPS Workshop

- 2021 LAMMPS Workshop

- REACTER website (reacter.org)

## 6.2.79. REAXFF package

Contents:

A pair style which implements the ReaxFF potential in C/C++. ReaxFF is a universal reactive force field. See the src/REAXFF/README file for more info on differences between the two packages. Also two fixes for monitoring molecules as bonds are created and destroyed.

Author: Hasan Metin Aktulga (MSU) while at Purdue University.

Supporting info:

- src/REAXFF: filenames -> commands

- src/REAXFF/README

- pair_style reaxff

- fix reaxff/bonds

- fix reaxff/species

- examples/reaxff

## 6.2.80. REPLICA package

Contents:

A collection of multi-replica methods which can be used when running multiple LAMMPS simulations (replicas). See the Howto replica page for an overview of how to run multi-replica simulations in LAMMPS. Methods in the package include nudged elastic band (NEB), parallel replica dynamics (PRD), temperature accelerated dynamics (TAD), parallel tempering, and a verlet/split algorithm for performing long-range Coulombics on one set of processors, and the remainder of the force field calculation on another set.

Supporting info:

- src/REPLICA: filenames -> commands

- Howto replica

- neb

- prd

- tad

- temper,

- temper/npt,

- temper/grem,

- run_style verlet/split

- examples/neb

- examples/prd

- examples/tad

- examples/PACKAGES/grem

## 6.2.81. RIGID package

Contents:

Fixes which enforce rigid constraints on collections of atoms or particles. This includes SHAKE and RATTLE, as well as various rigid-body integrators for a few large bodies or many small bodies. Also several computes which calculate properties of rigid bodies.

Supporting info:

- src/RIGID: filenames -> commands

- compute erotate/rigid

- fix shake

- fix rattle

- fix rigid/*

- examples/ASPHERE

- examples/rigid

- bench/in.rhodo

- https://www.lammps.org/movies.html#box

- https://www.lammps.org/movies.html#star

## 6.2.82. SCAFACOS package

Contents:

A KSpace style which wraps the ScaFaCoS Coulomb solver library to compute long-range Coulombic interactions.

To use this package you must have the ScaFaCoS library available on your system.

Author: Rene Halver (JSC) wrote the scafacos LAMMPS command.

ScaFaCoS itself was developed by a consortium of German research facilities with a BMBF (German Ministry of Science and Education) funded project in 2009-2012. Participants of the consortium were the Universities of Bonn, Chemnitz, Stuttgart, and Wuppertal as well as the Forschungszentrum Juelich.

Install:

This package has specific installation instructions on the Build extras page. The SCAFACOS package requires that LAMMPS is build in MPI parallel mode.

Supporting info:

- src/SCAFACOS: filenames -> commands

- src/SCAFACOS/README

- kspace_style scafacos

- kspace_modify

- examples/PACKAGES/scafacos

## 6.2.83. SHOCK package

Contents:

Fixes for running impact simulations where a shock-wave passes through a material.

Supporting info:

- src/SHOCK: filenames -> commands

- fix append/atoms

- fix msst

- fix nphug

- fix wall/piston

- examples/hugoniostat

- examples/msst

## 6.2.84. SMTBQ package

Contents:

Pair styles which implement Second Moment Tight Binding models. One with QEq charge equilibration (SMTBQ) for the description of ionocovalent bonds in oxides, and two more as plain SMATB models.

Authors: SMTBQ: Nicolas Salles, Emile Maras, Olivier Politano, and Robert Tetot (LAAS-CNRS, France); SMATB: Daniele Rapetti (Politecnico di Torino)

Supporting info:

- src/SMTBQ: filenames -> commands

- src/SMTBQ/README

- pair_style smtbq

- pair_style smatb, pair_style smatb/single

- examples/PACKAGES/smtbq

## 6.2.85. SPH package

Contents:

An atom style, fixes, computes, and several pair styles which implements smoothed particle hydrodynamics (SPH) for liquids. See the related MACHDYN package package for smooth Mach dynamics (SMD) for solids.

This package contains ideal gas, Lennard-Jones equation of states, Tait, and full support for complete (i.e. internal-energy dependent) equations of state. It allows for plain or Monaghans XSPH integration of the equations of motion. It has options for density continuity or density summation to propagate the density field. It has set command options to set the internal energy and density of particles from the input script and allows the same quantities to be output with thermodynamic output or to dump files via the compute property/atom command.

Author: Georg Ganzenmuller (Fraunhofer-Institute for High-Speed Dynamics, Ernst Mach Institute, Germany).

Supporting info:

- src/SPH: filenames -> commands

- src/SPH/README

- doc/PDF/SPH_LAMMPS_userguide.pdf

- examples/PACKAGES/sph

- https://www.lammps.org/movies.html#sph

## 6.2.86. SPIN package

Contents:

Model atomic magnetic spins classically, coupled to atoms moving in the usual manner via MD. Various pair, fix, and compute styles.

Author: Julien Tranchida (Sandia).

Supporting info:

- src/SPIN: filenames -> commands

- Howto spins

- pair_style spin/dipole/cut

- pair_style spin/dipole/long

- pair_style spin/dmi

- pair_style spin/exchange

- pair_style spin/exchange/biquadratic

- pair_style spin/magelec

- pair_style spin/neel

- fix nve/spin

- fix langevin/spin

- fix precession/spin

- compute spin

- neb/spin

- examples/SPIN

## 6.2.87. SRD package

Contents:

A pair of fixes which implement the Stochastic Rotation Dynamics (SRD) method for coarse-graining of a solvent, typically around large colloidal particles.

Supporting info:

- src/SRD: filenames -> commands

- fix srd

- fix wall/srd

- examples/srd

- examples/ASPHERE

- https://www.lammps.org/movies.html#tri

- https://www.lammps.org/movies.html#line

- https://www.lammps.org/movies.html#poly

## 6.2.88. TALLY package

Contents:

Several compute styles that can be called when pairwise interactions are calculated to tally information (forces, heat flux, energy, stress, etc) about individual interactions.

Author: Axel Kohlmeyer (Temple U).

Supporting info:

- src/TALLY: filenames -> commands

- src/TALLY/README

- compute */tally

- examples/PACKAGES/tally

## 6.2.89. UEF package

Contents:

A fix style for the integration of the equations of motion under extensional flow with proper boundary conditions, as well as several supporting compute styles and an output option.

Author: David Nicholson (MIT).

Supporting info:

- src/UEF: filenames -> commands

- src/UEF/README

- fix nvt/uef

- fix npt/uef

- compute pressure/uef

- compute temp/uef

- dump cfg/uef

- examples/uef

## 6.2.90. VORONOI package

Contents:

A compute command which calculates the Voronoi tesselation of a collection of atoms by wrapping the Voro++ library. This can be used to calculate the local volume or each atoms or its near neighbors.

To use this package you must have the Voro++ library available on your system.

Author: Daniel Schwen (INL) while at LANL. The open-source Voro++ library was written by Chris Rycroft (Harvard U) while at UC Berkeley and LBNL.

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/VORONOI: filenames -> commands

- src/VORONOI/README

- lib/voronoi/README

- compute voronoi/atom

- examples/voronoi

## 6.2.91. VTK package

Contents:

A dump vtk command which outputs snapshot info in the VTK format, enabling visualization by Paraview or other visualization packages.

To use this package you must have VTK library available on your system.

Authors: Richard Berger (JKU) and Daniel Queteschiner (DCS Computing).

Install:

This package has specific installation instructions on the Build extras page.

Supporting info:

- src/VTK: filenames -> commands

- src/VTK/README

- lib/vtk/README

- dump vtk

## 6.2.92. YAFF package

Contents:

Some potentials that are also implemented in the Yet Another Force Field (YAFF) code. The expressions and their use are discussed in the following papers

- Vanduyfhuys et al., J. Comput. Chem., 36 (13), 1015-1027 (2015) link

- Vanduyfhuys et al., J. Comput. Chem., 39 (16), 999-1011 (2018) link

which discuss the QuickFF methodology.

Author: Steven Vandenbrande.

New in version 1Feb2019.

Supporting info:

- src/YAFF/README

- angle_style cross

- angle_style mm3

- bond_style mm3

- improper_style distharm

- improper_style sqdistharm

- pair_style mm3/switch3/coulgauss/long

- pair_style lj/switch3/coulgauss/long

- examples/PACKAGES/yaff