.. index:: libint
.. _libint:

libint
======

Description
-----------

Libint is a high-performance library for computing Gaussian integrals in quantum mechanics.

User instructions
-----------------

The most recent version can be loaded with

.. code-block:: bash

    $ module libint/2.3.1

Documentation is available at the `libint website <http://libint.valeyev.net/>`_, and also at
`their sourceforge page <https://sourceforge.net/p/libint/home/>`_.

Source
------

https://github.com/evaleev/libint

License
-------

GNU General Public License (v2 or later).

Admin notes
-----------

The compilation was done as:

.. code-block:: bash

    ml intel
    ./autogen.sh
    mkdir ../build-2.3.1-intel2017; cd ../build-2.3.1-intel2017
    ../libint-2.3.1/configure --enable-shared --prefix=/common/debian/9.1/Compiler/intel/2017.4/libint/libint-2.3.1 --enable-1body=1 --enable-eri=1 --enable-eri3=1 --enable-eri2=1 --enable-contracted-ints --with-max-am=7 --with-opt-am=2 --with-cxxgen-optflags='-O3' CXX=icpc CC=icc
    make
    make install


Note - the various other things that are enabled are needed for molgw compilation. When enabled the libint compilation will take several days in serial and lead to a folder close to 7G in size. Possibly reducing the optimization level to O2 could cut the compile time somewhat.