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dft_tools/doc/tutorials/sr2mgoso6_nosoc.rst
2020-03-30 15:55:02 +02:00

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.. _Sr2MgOsO6_noSOC:
Here we will discuss a calculation where off-diagonal matrix elements show up, and will discuss step-by-step how this calculation can be set up.
The full script for this calculation is also provided here (:download:`Sr2MgOsO6_noSOC.py <images_scripts/Sr2MgOsO6_noSOC.py>`).
Note that we do not include spin-orbit coupling here for pedagogical reasons. For the real material it is necessary to include also SOC.
DFT (Wien2k) and Wannier orbitals
=================================
DFT setup
---------
First, we do a DFT calculation, using the Wien2k package. As main input file we have to provide the so-called struct file :file:`Sr2MgOs6_noSOC.struct`. We use the following:
.. literalinclude:: images_scripts/Sr2MgOsO6_noSOC.struct
The DFT calculation is done as usual, for instance you can use for the initialisation
init -b -vxc 5 -numk 2000
This is setting up a non-magnetic calculation, using the LDA and 2000 k-points in the full Brillouin zone. As usual, we start the DFT self consistent cycle by the Wien2k script ::
run
Wannier orbitals
----------------
As a next step, we calculate localised orbitals for the t2g orbitals. We use the same input file for :program:`dmftproj` as it was used in the :ref:`documentation`:
.. literalinclude:: images_scripts/Sr2MgOsO6_noSOC.indmftpr
Note that, due to the distortions in the crystal structure, we need to include all five d orbitals in the calculation (line 8 in the input file above).
To prepare the input data for :program:`dmftproj` we execute lapw2 with the `-almd` option ::
x lapw2 -almd
Then :program:`dmftproj` is executed in its default mode (i.e. without spin-polarization or spin-orbit included) ::
dmftproj
This program produces the necessary files for the conversion to the hdf5 file structure. This is done using
the python module :class:`Wien2kConverter <dft.converters.wien2k_converter.Wien2kConverter>`. A simple python script that initialises the converter is::
from triqs_dft_tools.converters.wien2k_converter import *
Converter = Wien2kConverter(filename = "Sr2MgOsO6_noSOC")
After initializing the interface module, we can now convert the input
text files to the hdf5 archive by::
Converter.convert_dft_input()
This reads all the data, and stores everything that is necessary for the DMFT calculation in the file :file:`Sr2MgOsO6_noSOC.h5`.
[CONTINUE HERE]
The DMFT calculation
====================