mirror of
https://github.com/QuantumPackage/qp2.git
synced 2024-11-04 13:13:53 +01:00
161 lines
3.0 KiB
ReStructuredText
161 lines
3.0 KiB
ReStructuredText
|
.. _module_fci:
|
||
|
|
|
||
|
|
.. program:: fci
|
||
|
|
|
||
|
|
.. default-role:: option
|
||
|
|
|
||
|
|
===
|
||
|
|
fci
|
||
|
|
===
|
||
|
|
|
||
|
|
|
||
|
|
|CIPSI| algorithm in the full configuration interaction space.
|
||
|
|
|
||
|
|
|
||
|
|
The user point of view
|
||
|
|
----------------------
|
||
|
|
|
||
|
|
* :ref:`fci` performs |CIPSI| calculations using a stochastic scheme for both
|
||
|
|
the selection and the |PT2| contribution,
|
||
|
|
|
||
|
|
* :ref:`pt2` computes the |PT2| contribution using the wave function stored in
|
||
|
|
the |EZFIO| database.
|
||
|
|
|
||
|
|
|
||
|
|
The main keywords/options for this module are:
|
||
|
|
|
||
|
|
* :option:`determinants n_det_max` : maximum number of Slater determinants in
|
||
|
|
the |CIPSI| wave function. The :ref:`fci` program will stop when the size of
|
||
|
|
the |CIPSI| wave function will exceed :option:`determinants n_det_max`.
|
||
|
|
|
||
|
|
* :option:`perturbation pt2_max` : absolute value of the |PT2| to stop the
|
||
|
|
|CIPSI| calculation. Once the abs(|PT2|) :math:`<` :option:`perturbation pt2_max`,
|
||
|
|
the |CIPSI| calculation stops.
|
||
|
|
|
||
|
|
* :option:`determinants n_states` : number of states to consider in the |CIPSI|
|
||
|
|
calculation.
|
||
|
|
|
||
|
|
* :option:`determinants read_wf` : if |false|, starts with a |ROHF|-like
|
||
|
|
determinant, if |true|, starts with the current wave function(s) stored in
|
||
|
|
the |EZFIO| directory.
|
||
|
|
|
||
|
|
.. note::
|
||
|
|
For a multi-state calculation, it is recommended to start with :ref:`cis`
|
||
|
|
or :ref:`cisd` wave functions as a guess.
|
||
|
|
|
||
|
|
* :option:`determinants expected_s2` : expected value of |S^2| for the
|
||
|
|
desired spin multiplicity.
|
||
|
|
|
||
|
|
* :option:`determinants s2_eig` : if |true|, systematically add all the
|
||
|
|
determinants needed to have a pure value of |S^2|. Also, if |true|, it
|
||
|
|
tracks only the states having the good :option:`determinants expected_s2`.
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
The programmer's point of view
|
||
|
|
------------------------------
|
||
|
|
|
||
|
|
This module was created with the :ref:`module_cipsi` module.
|
||
|
|
|
||
|
|
.. seealso::
|
||
|
|
|
||
|
|
The documentation of the :ref:`module_cipsi` module.
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
EZFIO parameters
|
||
|
|
----------------
|
||
|
|
|
||
|
|
.. option:: energy
|
||
|
|
|
||
|
|
Calculated Selected |FCI| energy
|
||
|
|
|
||
|
|
|
||
|
|
.. option:: energy_pt2
|
||
|
|
|
||
|
|
Calculated |FCI| energy + |PT2|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
Programs
|
||
|
|
--------
|
||
|
|
|
||
|
|
* :ref:`fci`
|
||
|
|
* :ref:`pt2`
|
||
|
|
|
||
|
|
Providers
|
||
|
|
---------
|
||
|
|
|
||
|
|
.. c:var:: do_ddci
|
||
|
|
|
||
|
|
|
||
|
|
File : :file:`fci/class.irp.f`
|
||
|
|
|
||
|
|
.. code:: fortran
|
||
|
|
|
||
|
|
logical :: do_only_1h1p
|
||
|
|
logical :: do_ddci
|
||
|
|
|
||
|
|
|
||
|
|
In the FCI case, all those are always false
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
.. c:var:: do_only_1h1p
|
||
|
|
|
||
|
|
|
||
|
|
File : :file:`fci/class.irp.f`
|
||
|
|
|
||
|
|
.. code:: fortran
|
||
|
|
|
||
|
|
logical :: do_only_1h1p
|
||
|
|
logical :: do_ddci
|
||
|
|
|
||
|
|
|
||
|
|
In the FCI case, all those are always false
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
Subroutines / functions
|
||
|
|
-----------------------
|
||
|
|
|
||
|
|
.. c:function:: save_energy:
|
||
|
|
|
||
|
|
|
||
|
|
File : :file:`fci/save_energy.irp.f`
|
||
|
|
|
||
|
|
.. code:: fortran
|
||
|
|
|
||
|
|
subroutine save_energy(E,pt2)
|
||
|
|
|
||
|
|
|
||
|
|
Saves the energy in |EZFIO|.
|
||
|
|
|
||
|
|
Needs:
|
||
|
|
|
||
|
|
.. hlist::
|
||
|
|
:columns: 3
|
||
|
|
|
||
|
|
* :c:data:`n_states`
|
||
|
|
|
||
|
|
Called by:
|
||
|
|
|
||
|
|
.. hlist::
|
||
|
|
:columns: 3
|
||
|
|
|
||
|
|
* :c:func:`run_cipsi`
|
||
|
|
* :c:func:`run_stochastic_cipsi`
|
||
|
|
|
||
|
|
Calls:
|
||
|
|
|
||
|
|
.. hlist::
|
||
|
|
:columns: 3
|
||
|
|
|
||
|
|
* :c:func:`ezfio_set_fci_energy`
|
||
|
|
* :c:func:`ezfio_set_fci_energy_pt2`
|
||
|
|
|