LAMMPS is a classical molecular dynamics code. It can be applied to metals, semiconductors, biomolecules, polymers in all-atom or coarse-grained models. The source code is distributed under the terms of GPL by Sandia National Laboratories. See LAMMPS home page http://lammps.sandia.gov/ for additional information.
B. How to download LAMMPS
There are several different mechanisms to download LAMMPS. See complete instructions for downloading the code. To download a stable version of the code to local directory mylammps by using svn tool, use the following command
svn co -r N svn://svn.lammps.org/lammps-ro/trunk mylammps
where N is SVN tag. For the recent stable version 1 Feb 2014, the tag N is 11423. The LAMMPS web site supplies the list of a few stable versions. To download the latest version, use
svn co svn://svn.lammps.org/lammps-ro/trunk mylammps
C. How to build LAMMPS
On Cray XE6 platform, LAMMPS can be built under GNU or PGI environments. Following instructions are tested on 1 Feb 2014 release.
C.1 Building under GNU environment
Successful compilation will create lmp_xe6 binary file. A few comments should be made. Althought the February 1, 2014 release comes with Makefile.xe6 for Cray XE6 pltaform included into the distribution, that Makefile.xe6 is not functional. We made following changes to correct it:
C.2 Building under PGI environment
Successful compilation will create lmp_xe6 binary file. Again, as in the previous case, Makefile.xe6 needs a few corrections:
D. Sample test
LAMMPS comes with an extensive suit of tests. To make sure that the compiled code works, we wil run one of the supplied tests.
Open the file job.out with text editor and make sure that line "Loop time of 7.75093 on 4 procs for 60000 steps with 1200 atoms" is present near the end of the file. This is 21st line from the bottom. It indicates that the job performed 60,000 dynamics steps on 4 processors. Timing of 7.75093 will be different on different machines and may somewhat vary from run to run, which is normal.