********
Gaussian
********

.. py:class:: Gaussian

This interface supports energy and gradient evaluations with the
`Gaussian <https://gaussian.com/>`_ electronic structure package
(v16)

A Gaussian :ref:`Theory <theories>` object can be specified as follows::

  my_frag = Fragment(...)

  my_theory = Gaussian(frag=my_frag,
                       method='hf',
                       basis='3-21g',
                       ...)

which would then be called as ``theory=my_theory`` in subsequent tasks
(see :ref:`Tasks <tasks>`).


General options
===============

.. py:attribute:: check

   (default: ``'_gaussian.chk'``) Gaussian check filename

.. py:attribute:: input

   (default: ``'_gaussian.inp'``) Gaussian input filename

.. py:attribute:: output

   (default: ``'_gaussian.log'``) Gaussian output filename

SCF options
===========

.. py:attribute:: threshold

   (default: ``1.0E-8``) SCF energy convergence threshold