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QuantumPackage/docs/source/programs/scf.rst

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.. _scf:
.. program:: scf
===
scf
===
The :ref:`scf` program performs *Restricted* Hartree-Fock
calculations (the spatial part of the |MOs| is common for alpha and beta
spinorbitals).
It performs the following actions:
#. Compute/Read all the one- and two-electron integrals, and store them
in memory
#. Check in the |EZFIO| database if there is a set of |MOs|.
If there is, it will read them as initial guess. Otherwise, it will
create a guess.
#. Perform the |SCF| iterations
For the keywords related to the |SCF| procedure, see the ``scf_utils``
directory where you will find all options.
At each iteration, the |MOs| are saved in the |EZFIO| database. Hence,
if the calculation crashes for any unexpected reason, the calculation
can be restarted by running again the |SCF| with the same |EZFIO|
database.
To start again a fresh |SCF| calculation, the |MOs| can be reset by
running the :ref:`qp_reset` command.
The `DIIS`_ algorithm is implemented, as well as the `level-shifting`_
method. If the |SCF| does not converge, try again with a higher value of
:option:`level_shift`.
.. _DIIS: https://en.wikipedia.org/w/index.php?title=DIIS
.. _level-shifting: https://doi.org/10.1002/qua.560070407
Calls:
.. hlist::
:columns: 3
* :c:func:`create_guess`
* :c:func:`orthonormalize_mos`
* :c:func:`run`
Touches:
.. hlist::
:columns: 3
* :c:data:`fock_matrix_ao_alpha`
* :c:data:`fock_matrix_ao_alpha`
* :c:data:`mo_coef`
* :c:data:`mo_label`