.. _Gamess:

Gamess
======

De acordo com o `página do Gamess <https://www.msg.chem.iastate.edu/gamess/>`_,
"*GAMESS is a program for ab initio molecular quantum chemistry. Briefly,
GAMESS can compute SCF wavefunctions ranging from RHF, ROHF, UHF, GVB, and
MCSCF. Correlation corrections to these SCF wavefunctions include Configuration
Interaction, second order perturbation Theory, and Coupled-Cluster approaches,
as well as the Density Functional Theory approximation. Excited states can be
computed by CI, EOM, or TD-DFT procedures. Nuclear gradients are available, for
automatic geometry optimization, transition state searches, or reaction path
following. Computation of the energy hessian permits prediction of vibrational
frequencies, with IR or Raman intensities. Solvent effects may be modeled by
the discrete Effective Fragment potentials, or continuum models such as the
Polarizable Continuum Model. Numerous relativistic computations are available,
including infinite order two component scalar relativity corrections, with
various spin-orbit coupling options. The Fragment Molecular Orbital method
permits use of many of these sophisticated treatments to be used on very large
systems, by dividing the computation into small fragments. Nuclear
wavefunctions can also be computed, in VSCF, or with explicit treatment of
nuclear orbitals by the NEO code. A variety of molecular properties, ranging
from simple dipole moments to frequency dependent hyperpolarizabilities may be
computed. Many basis sets are stored internally, together with effective core
potentials or model core potentials, so that essentially the entire periodic
table can be considered.*".


Versões Disponíveis
-------------------

* gamess/2018 (default)
* gamess/2020


.. important::
   A versão 2018 do Gamess precisa de ao menos 2 processos (``-n 2``) para ser
   executado. Essa versão não funciona serialmente no cluster. Lembrando que
   sempre se deve escolher um valor **PAR** de processos.


Submissão de Jobs em Paralelo
-----------------------------

Crie um arquivo chamado, por exemplo, *submit_paral_jobs.sh*.

.. code-block:: bash

   #!/bin/bash
   #SBATCH -t 23:00:00 -n 16

   export INPUT="gamess-parallel.inp"
   export OUTPUT="*"

   module load gamess/2018
   job-nanny gamess.sh gamess-parallel.inp


Para submeter o processo, basta usar o comando:

.. code-block:: bash

   sbatch submit_paral_jobs.sh



Referências
-----------

Para informações adicionais sobre o software, consulte a `página do Gamess <https://www.msg.chem.iastate.edu/gamess/>`_.