qp2/docs/source/modules/dft_keywords.rst

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.. _module_dft_keywords:
.. program:: dft_keywords
.. default-role:: option
============
dft_keywords
============
This module contains the main keywords related to a DFT calculation or RS-DFT calculation.
These keywords are related to the following programs of the |QP| core modules:
* :ref:`ks_scf` : Kohn-Sham |DFT|
* :ref:`rs_ks_scf` : Range separated Hybrids |DFT|
Modifying the exchange/correlation functionals
----------------------------------------------
To modify the exchange/correlation functionals, see the following keywords:
* :option:`dft_keywords exchange_functional`: type of exchange functionals
* :option:`dft_keywords correlation_functional`: type of correlation functionals
Each of these keywords can have the following value:
* "LDA" or "short_range_LDA" for, respectively the |LDA| and its short-range version
* "PBE" or "short_range_PBE" for, respectively the |PBE| and its short-range version
Modifying the amount of |HF| exchange
-------------------------------------
* :option:`dft_keywords HF_exchange` : only relevent for the :ref:`ks_scf` program
Other related keywords not defined in :ref:`module_dft_keywords`
----------------------------------------------------------------
The keyword for the **range separation parameter** :math:`\mu` is the :option:`ao_two_e_erf_ints mu_erf` keyword.
The keyword for the **type of density used in RS-DFT** calculation with a **multi-configurational wave function** is the :option:`density_for_dft density_for_dft` keyword.
EZFIO parameters
----------------
.. option:: exchange_functional
name of the exchange functional
Default: short_range_LDA
.. option:: correlation_functional
name of the correlation functional
Default: short_range_LDA
.. option:: HF_exchange
Percentage of HF exchange in the DFT model
Default: 0.
Providers
---------
.. c:var:: dft_type
File : :file:`dft_keywords/keywords.irp.f`
.. code:: fortran
character*(32) :: dft_type
defines the type of DFT applied: LDA, GGA etc ...
Needs:
.. hlist::
:columns: 3
* :c:data:`correlation_functional`
* :c:data:`exchange_functional`
.. c:var:: same_xc_func
File : :file:`dft_keywords/keywords.irp.f`
.. code:: fortran
logical :: same_xc_func
true if the exchange and correlation functionals are the same
Needs:
.. hlist::
:columns: 3
* :c:data:`correlation_functional`
* :c:data:`exchange_functional`
Needed by:
.. hlist::
:columns: 3
* :c:data:`ao_potential_alpha_xc`