lammps/examples/USER/i-pi

i-PI path integral interface examples
=====================================

This folder contains a couple of examples to run LAMMPS as a client,
exchanging information on the atomic configurations, energy and forces
with the i-PI Python interface
[http://epfl-cosmo.github.io/gle4md/index.html?page=ipi].  These
examples require a working copy of i-PI and compiling LAMMPS in a UNIX
environment.  Note that a copy of i-PI is provided with LAMMPS, in the
tools/i-pi directory.

Note that the i-PI examples listed here are designed for the public V1.0
version of i-PI. Refer to the LAMMPS examples distributed with i-PI if you
are using a development version.

Path integral simulation of graphene
------------------------------------

The example in this folder uses the external wrapper i-PI to perform 
path integral molecular dynamics simulation of a graphene sheet, using 
LAMMPS as the force back-end. The output is generated by i-PI. Please
refer to its documentation for an explanation of the input parameters
and the format of the output.

How to run i-PI
---------------

You should have a relatively recent (>=2.5) version of Python and Numpy,
and the public version of i-PI. You can then run i-PI by executing

```bash
   $PATHTOIPI/i-pi i-pi_input.xml
```

In a separate terminal, then, you should run LAMMPS compiled to provide 
fix_ipi functionalities.

```bash
   $LAMMPS < in.graphene
```

You can run multiple instances of LAMMPS if you want to exploit the 
parallelism over the path integral beads.