lammps/examples

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 "Additional Tools" section of the LAMMPS
documentation.  Animations of many of these examples can be viewed on
the Movies section of the LAMMPS WWW Site.

These are the sample problems and their output in the various
sub-directories:

colloid:  big colloid particles in a small particle solvent, 2d system
comb:	  models using the COMB potential
crack:	  crack propagation in a 2d solid
dipole:   point dipolar particles, 2d system
eim:      NaCl using the EIM potential
ellipse:  ellipsoidal particles in spherical solvent, 2d system
flow:	  Couette and Poiseuille flow in a 2d channel
friction: frictional contact of spherical asperities between 2d surfaces
indent:	  spherical indenter into a 2d solid
meam:	  MEAM test for SiC and shear (same as shear examples)
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
msst:	  MSST shock dynamics
neb:	  nudged elastic band (NEB) calculation for barrier finding
nemd:	  non-equilibrium MD of 2d sheared system
obstacle: flow around two voids in a 2d channel
peptide:  dynamics of a small solvated peptide chain (5-mer)
peri:	  Peridynamic model of cylinder impacted by indenter
pour:     pouring of granular particles into a 3d box, then chute flow
prd:      parallel replica dynamics of a vacancy diffusion in bulk Si
reax:     RDX and TATB models using the ReaxFF
rigid:    rigid bodies modeled as independent or coupled
shear:    sideways shear applied to 2d solid, with and without a void
srd:      stochastic rotation dynamics (SRD) particles as solvent

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

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There is also an ELASTIC directory with an example script for
computing elastic constants, using a zero temperature Si example.  See
the in.elastic file for more info.

There is also a USER directory which contains subdirectories of
user-provided examples for user packages.  See the README files in
those directories for more info.  See the doc/Section_start.html file
for more info about user packages.