# 3.2. Build LAMMPS with make

Building LAMMPS with traditional makefiles requires that you have a Makefile.”machine” file appropriate for your system in the src/MAKE, src/MAKE/MACHINES, src/MAKE/OPTIONS, or src/MAKE/MINE directory (see below). It can include various options for customizing your LAMMPS build with a number of global compilation options and features.

Those makefiles are written for and tested with GNU make and may not be compatible with other make programs. In most cases, if the “make” program is not GNU make, then there will be a GNU make program available under the name “gmake”. If GNU make or a compatible make is not available, you may have to first install it or switch to building with CMake. The makefiles of the traditional make based build process and the scripts they are calling expect a few additional tools to be available and functioning.

• a Bourne shell compatible “Unix” shell program (often this is bash)

• a few shell utilities: ls, mv, ln, rm, grep, sed, tr, cat, touch, diff, dirname

• python (optional, required for “make lib-XXX” in the src folder)

To include LAMMPS packages (i.e. optional commands and styles) you must enable them first, as discussed on the Build package doc page. If a packages requires (provided or external) libraries, you must configure and build those libraries before building LAMMPS itself and especially before enabling such a package with “make yes-<package>”. Building LAMMPS with CMake can automate much of this for many types of machines, especially workstations, desktops, and laptops, so we suggest you try it first when building LAMMPS in those cases.

The commands below perform a default LAMMPS build, producing the LAMMPS executable lmp_serial and lmp_mpi in lammps/src:

cd lammps/src
make serial     # build a serial LAMMPS executable
make mpi        # build a parallel LAMMPS executable with MPI
make            # see a variety of make options


This initial compilation can take a long time, since LAMMPS is a large project with many features. If your machine has multiple CPU cores (most do these days), using a command like “make -jN mpi” (with N = the number of available CPU cores) can be much faster. If you plan to do development on LAMMPS or need to re-compile LAMMPS repeatedly, the installation of the ccache (= Compiler Cache) software may speed up compilation even more.

After the initial build, whenever you edit LAMMPS source files, or add or remove new files to the source directory (e.g. by installing or uninstalling packages), you must re-compile and relink the LAMMPS executable with the same “make” command. This makefiles dependencies should insure that only the subset of files that need to be are re-compiled.

Note

Before the actual compilation starts, LAMMPS will perform several steps to collect information from the configuration and setup that is then embedded into the executable. When you build LAMMPS for the first time, it will also compile a tool to quickly assemble a list of dependencies, that are required for the make program to correctly detect which parts need to be recompiled after changes were made to the sources.

The lammps/src/MAKE tree contains the Makefile.machine files included in the LAMMPS distribution. Typing “make machine” uses Makefile.machine. Thus the “make serial” or “make mpi” lines above use Makefile.serial and Makefile.mpi, respectively. Other makefiles are in these directories:

OPTIONS      # Makefiles which enable specific options
MACHINES     # Makefiles for specific machines
MINE         # customized Makefiles you create (you may need to create this folder)


Typing “make” lists all the available Makefile.machine files. A file with the same name can appear in multiple folders (not a good idea). The order the directories are searched is as follows: src/MAKE/MINE, src/MAKE, src/MAKE/OPTIONS, src/MAKE/MACHINES. This gives preference to a customized file you put in src/MAKE/MINE.

Makefiles you may wish to try include these (some require a package first be installed). Many of these include specific compiler flags for optimized performance. Please note, however, that some of these customized machine Makefile are contributed by users. Since both compilers, OS configurations, and LAMMPS itself keep changing, their settings may become outdated:

make mac             # build serial LAMMPS on a Mac
make mac_mpi         # build parallel LAMMPS on a Mac
make intel_cpu       # build with the USER-INTEL package optimized for CPUs
make knl             # build with the USER-INTEL package optimized for KNLs
make opt             # build with the OPT package optimized for CPUs
make omp             # build with the USER-OMP package optimized for OpenMP
make kokkos_omp      # build with the KOKKOS package for OpenMP
make kokkos_cuda_mpi # build with the KOKKOS package for GPUs
make kokkos_phi      # build with the KOKKOS package for KNLs