LAMMPS example problems

Each of these sub-directories contains a sample problem you can run with LAMMPS. Most are 2d models so that they run quickly, requiring a few seconds to a few minutes to run on a desktop machine. Each problem has an input script (in.*) and produces a log file (log.*) and dump file (dump.*) when it runs. Some use a data file (data.*) of initial coordinates as additional input.

A few sample log file outputs on different machines and different numbers of processors are included in the directories to compare your answers to. E.g. a log file like log.crack.date.foo.P means it ran on P processors of machine "foo" with the dated version of LAMMPS. Note that these problems should get statistically similar answers when run on different machines or different numbers of processors, but not identical answers to those in the log of dump files included here. See the Errors section of the LAMMPS documentation for more discussion.

The dump files produced by the example runs can be animated using the xmovie tool described in the Examples section of the LAMMPS documentation. MPEG versions of most of the xmovie animations are also viewable from the Examples section of the LAMMPS WWW Site.

These are the sample problems in the various sub-directories:

couple: illustration of how to link to LAMMPS as a library crack: crack propagation in a 2d solid flow: Couette and Poisseuille flow in a 2d channel friction: frictional contact of spherical asperities between 2d surfaces indent: spherical indenter into a 2d solid melt: rapid melt of 3d LJ system micelle: self-assembly of small lipid-like molecules into 2d bilayers min: energy minimization of 2d LJ melt obstacle: flow around two voids in a 2d channel peptide: dynamics of a small solvated peptide chain (5-mer) pour: pouring of granular particles into a 3d box, then chute flow rigid: rigid bodies modeled as independent or coupled shear: sideways shear applied to 2d solid, with and without a void

Here is how you might run and visualize one of the sample problems:

cd indent cp ../../src/lmp_linux . # copy LAMMPS executable to this dir lmp_linux < in.indent # run the problem

Running the simulation produces the files dump.indent and log.lammps. You can visualize the dump file as follows:

../../tools/xmovie/xmovie -scale dump.indent