..
    : PyBEST: Pythonic Black-box Electronic Structure Tool
    : Copyright (C) 2016-- The PyBEST Development Team
    :
    : This file is part of PyBEST.
    :
    : PyBEST is free software; you can redistribute it and/or
    : modify it under the terms of the GNU General Public License
    : as published by the Free Software Foundation; either version 3
    : of the License, or (at your option) any later version.
    :
    : PyBEST is distributed in the hope that it will be useful,
    : but WITHOUT ANY WARRANTY; without even the implied warranty of
    : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    : GNU General Public License for more details.
    :
    : You should have received a copy of the GNU General Public License
    : along with this program; if not, see <http://www.gnu.org/licenses/>
    : --


.. _ea_examples:

Example Python scripts
======================

Several complete examples can be found in the directory ``data/examples/ea``.

EA-pCCD calculations on the :math:`\textrm{O}_2` molecule for 1 and 3 unpaired electrons
----------------------------------------------------------------------------------------

This is a basic example of how to perform an EA-pCCD calculation in PyBEST.
This script performs an RHF calculation, followed by a pCCD calculation, and
finally an EA calculation with a pCCD reference function on the oxygen molecule
using the cc-pVDZ basis set. First, only one unpaired electron is considered
(doublet and quartet states). In the second calculation, only the quartet states are targeted (3 unpaired electrons)

.. literalinclude:: ../src/pybest/data/examples/ea_eom/reapccd_o2_cc-pvdz.py
    :caption: data/examples/ea_eom/reapccd_o2_cc-pvdz.py.py
    :lines: 3-


DEA-pCCD calculations on the :math:`\textrm{O}_2` molecule for 0 and 2 unpaired electrons
-----------------------------------------------------------------------------------------

This is a basic example of how to perform a DEA-pCCD calculation in PyBEST.
This script performs an RHF calculation followed by a pCCD calculation, and
finally a DEA calculation with a pCCD reference function on the :math:`\textrm{O}_2` molecule
using the cc-pVDZ basis set. First, no unpaired electrons are considered (singlet, triplet, and
quintet states). In the second calculation, only the triplet and quintet states are targeted
(2 unpaired electrons). In the third only quintet states are targeted (3 unpaired electrons).

.. literalinclude:: ../src/pybest/data/examples/ea_eom/rdeapccd_o2_cc-pvdz.py
    :caption: data/examples/ea/rdeapccd_o2_cc-pvdz.py
    :lines: 3-


EA-CCSD calculations on the NO molecule and one unpaired electron
-----------------------------------------------------------------

This is a basic example of how to perform an EA-CCSD calculation in PyBEST.
This script performs an RHF calculation, followed by a CCSD calculation, and one
EA-CCSD calculation on the NO molecule using the cc-pVDZ basis set and
targeting one unpaired electron (doublet and quartet states).

.. literalinclude:: ../src/pybest/data/examples/ea_eom/reaccsd_no_cc-pvdz.py
    :caption: data/examples/ea_eom/reaccsd_no_cc-pvdz.py
    :lines: 3-


EA-LCCD calculations on the NO molecule and one unpaired electron
-----------------------------------------------------------------

This is a basic example of how to perform an EA-LCCD calculation in PyBEST.
This script performs an RHF calculation, followed by an LCCD calculation, and one
EA-LCCD calculation on the NO molecule using the cc-pVDZ basis set and
targeting one unpaired electron (doublet and quartet states).

.. literalinclude:: ../src/pybest/data/examples/ea_eom/realccd_no_cc-pvdz.py
    :caption: data/examples/ea_eom/realccd_no_cc-pvdz.py
    :lines: 3-


EA-fpCCSD calculation on the NO molecule and one unpaired electron
------------------------------------------------------------------

This is a basic example of how to perform an EA-fpCCSD calculation in PyBEST.
This script performs an RHF calculation, followed by pCCD and fpCCSD calculations,
and an EA-fpCCSD calculation on the NO molecule using the cc-pVDZ basis set, targeting
one unpaired electron (doublet and quartet states).
A similar example for EA-fpCCD is provided in the ``data/examples/ea_eom/`` directory.

.. literalinclude:: ../src/pybest/data/examples/ea_eom/reafpccsd_no_cc-pvdz.py
    :caption: data/examples/ea_eom/reafpccsd_no_cc-pvdz.py
    :lines: 3-


EA-fpLCCSD calculation on the NO molecule and one unpaired electron
-------------------------------------------------------------------

This is a basic example of how to perform an EA-fpLCCSD calculation in PyBEST.
This script performs an RHF calculation, followed by pCCD and fpLCCSD calculations,
and an EA-fpLCCSD calculation on the NO molecule using the cc-pVDZ basis set,
targeting one unpaired electron (doublet and quartet states).
A similar example for EA-fpCCD is provided in the ``data/examples/ea_eom/`` directory.

.. literalinclude:: ../src/pybest/data/examples/ea_eom/reafplccsd_no_cc-pvdz.py
    :caption: data/examples/ea_eom/reafplccsd_no_cc-pvdz.py
    :lines: 3-


Cholesky-decomposed EA examples
-------------------------------

For computational efficiency, all EA models are also available using Cholesky-decomposed
integrals. Below, we show an example for EA-fpCCSD only. Other examples are collected in the
example directory.

.. literalinclude:: ../src/pybest/data/examples/ea_eom/reafpccsd_no_cc-pvdz_cholesky.py
    :caption: data/examples/ea_eom/reafpccsd_no_cc-pvdz_cholesky.py
    :lines: 3-