.. _installation:

============
Installation
============

Eon is divided up into two separate programs: a server and a client. The client
does most of the computation (`e.g.` saddle searches, minimizations, and
molecular dynamics) while the server creates the input for the client and
processes its results.

Dependencies
============

* Server
    * `Python <http://www.python.org/download>`_ (>=3.5)
    * `NumPy <http://new.scipy.org/download.html>`_ (>=1.2.1)
    * `ASE <https://wiki.fysik.dtu.dk/ase/download.html>`_
    * `PyYaml <https://pyyaml.org>`_
    * (optional, for MPI communicator) `mpi4py <http://mpi4py.scipy.org/>`_

* Client
    * GNU Make
    * G++ (>=4.0, other C++ compilers might work)
    * (optional) gfortran or Intel Fortran Compiler
    * (optional, for LAMMPS potentials) `LAMMPS <http://lammps.sandia.gov/doc/>`__

.. highlight:: bash

Server Installation
===================

We recommend installing Eon to your ``$HOME`` folder. To download the
latest developer version to your home folder::

    $ cd $HOME
    $ svn co https://theory.cm.utexas.edu/svn/eon

The directory ``$HOME/eon`` needs to be added to your ``$PYTHONPATH``
environment variable. It is also recommended to add ``$HOME/eon/bin`` to your
``$PATH``. This can be done permanetly by appending the following to your
``~/.profile`` file::

    export PYTHONPATH=$HOME/eon:$PYTHONPATH
    export PATH=$HOME/eon/bin:$PATH

If you have root permissions, you can install Eon system-wide::

    $ cd eon
    $ sudo python setup.py install

This will install the eon python module to Python's site-package directory
as well as adding the ``eon`` program to your ``$PATH``.

Client Installation
===================

The client source code is located in a folder named ``client`` under the main
eon directory.  For most situations you will only need to run the make command
and a binary named ``client`` will be built in this directory::

    $ cd client
    $ make

If you wish to use the potentials that depend on fortran you will need a
fortran compiler. However, this is optional and you can compile the client
without fortran support by running the command ``make NO_FORTRAN=1``. If you
are using gfortran the supplied Makefile should work out of the box. If you are
using the Intel Fortran Compiler (ifort) you will need to edit the Makefile to
change ``FC`` (fortran compiler), ``FFLAGS`` (fortran compiler flags), and
``FAR`` (fortran archiver) variables to work for your system.

If you wish to use a LAMMPS potential, you must first build the appropriate library version of LAMMPS.  If the library will be used with a serial version of EON, then build the serial version of LAMMPS--likewise for MPI use. 
Detailed documentation can be found on the :ref:`LAMMPS Potential<lammps_potential>` page. [#lammps]_

If you want to use the MPI communicator, see the :ref:`MPI
Communicator<communicator-mpi>` page for instructions.

For most installations, the binary ``eonclient`` can be copied to a directory in your
``$PATH``. If you added ``$HOME/eon/bin`` to your path
during the server installation the following command will install the client::

    $ cp eonclient ../bin/eonclient

Otherwise you will need to give the path to the client binary in your
``config.ini``. 

.. [#lammps] `"Large-scale Atomic/Molecular Massively Parallel Simulator,  Sandia National Laboratories" <http://http://lammps.sandia.gov/>`_