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Update for analysis.rst

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Manuel Zingl 2015-08-18 18:56:59 +02:00
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doc/guide/analysis.rst
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@ -21,30 +21,9 @@ However, a real frequency self energy has to be provided by the user to use the
There are methods included e.g. in the :program:`ALPS` package, which can be used for these purposes.
Keep in mind that all these methods have to be used very carefully!
Most conveniently, you have your self energy already stored as a real frequency :class:`BlockGf` object
in a hdf5 file, which can be easily loaded::
ar = HDFArchive(filename+'.h5','r')
SigmaReFreq = ar['SigmaReFreq']
del ar
.. note::
What happens if one has a self energy only in text files...?
You may also store it in text files. If all blocks of your self energy are of dimension 1x1, you store them in `fname_(block)0.dat` files. Here `(block)` is a block name (`up`, `down`, or combined `ud`). In the case when you have matrix blocks, you store them in `(i)_(j).dat` files, where `(i)` and `(j)` are the orbital indices, in the `fname_(block)` directory.
This self energy is loaded and put into the :class:`SumkDFT` class by the function::
SK.constr_Sigma_real_axis(filename, hdf=True, hdf_dataset='SigmaReFreq',n_om=0)
where:
* `filename`: the name of the hdf5 archive file or the `fname` pattern in text files names as described above,
* `hdf`: if `True`, the real-axis self energy will be read from the hdf5 file, otherwise from the text files,
* `hdf_dataset`: the name of dataset where the self energy is stored in the hdf5 file,
* `n_om`: the number of points in the real-axis mesh (used only if `hdf=False`).
The chemical potential as well as the double counting correction were already read in the initialisation process.
Add the doc for loading the self energy from a data file. We have to provide this option, because
in general the user won't has it stored in h5 file!!
Initialisation
--------------
@ -61,45 +40,51 @@ class::
Note that all routines available in :class:`SumkDFT` are also available here.
If required, the real frequency self energy is set with::
If required, a self energy is load and initialise in the next step. Most conveniently,
your self energy is already stored as a real frequency :class:`BlockGf` object
in a hdf5 file::
SK.put_Sigma(Sigma_imp = [ SigmaReFreq ])
ar = HDFArchive(filename+'.h5','r')
SigmaReFreq = ar['SigmaReFreq']
SK.put_Sigma(Sigma_imp = [ SigmaReFreq ])
del ar
Additionally, the chemical potential and the double counting correction are set with::
SK.chemical_potential = chemical_potential
SK.dc_imp = dc_imp
Density of states of the Wannier orbitals
-----------------------------------------
For plotting the
density of states of the Wannier orbitals, you simply type::
For plotting the density of states of the Wannier orbitals, you type::
SK.check_input_dos(om_min, om_max, n_om)
SK.dos_wannier_basis(broadening=0.03, mesh=[om_min, om_max, n_om], with_Sigma=False, with_dc=False, save_to_file=True)
which produces plots between the real frequencies `om_min` and `om_max`, using a mesh of `n_om` points. There
is an optional parameter `broadening` which defines an additional Lorentzian broadening, and has the default value of
`0.01` by default.
which produces plots between the real frequencies `om_min` and `om_max`, using a mesh of `n_om` points. The parameter
`broadening` defines an additional Lorentzian broadening, and has the default value of `0.01` eV. To check the Wannier
density of states after the projection set `with_Sigma` and `with_dc` to `False`.
Partial charges
---------------
Since we can calculate the partial charges directly from the Matsubara Green's functions, we also do not need a
real-frequency self energy for this purpose. The calculation is done by::
real frequency self energy for this purpose. The calculation is done by::
ar = HDFArchive(SK.hdf_file)
SK.put_Sigma([ ar['SigmaImFreq'] ])
del ar
dm = SK.partial_charges()
SK.put_Sigma(Sigma_imp = SigmaImFreq)
dm = SK.partial_charges(beta=40.0 with_Sigma=True, with_dc=True)
which calculates the partial charges using the data stored in the hdf5 file, namely the self energy, double counting, and
chemical potential. Here we assumed that the final self energy is stored as `SigmaImFreq` in the archive.
On return, `dm` is a list, where the list items correspond to the density matrices of all shells
which calculates the partial charges using the self energy, double counting, and chemical potential as set in the
`SK` object. On return, `dm` is a list, where the list items correspond to the density matrices of all shells
defined in the list `SK.shells`. This list is constructed by the Wien2k converter routines and stored automatically
in the hdf5 archive. For the detailed structure of `dm`, see the reference manual.
Correlated spectral function (with self energy)
-----------------------------------------------
Correlated spectral function (with real frequency self energy)
--------------------------------------------------------------
With this self energy, we can now execute::
SK.dos_partial(broadening=broadening)
SK.dos_parproj_basis(broadening=broadening)
This produces both the momentum-integrated (total density of states or DOS) and orbitally-resolved (partial/projected DOS) spectral functions.
The variable `broadening` is an additional Lorentzian broadening applied to the resulting spectra.
@ -112,8 +97,8 @@ The output is printed into the files
* `DOScorr(sp)_proj(i)_(m)_(n).dat`: As above, but printed as orbitally-resolved matrix in indices
`(m)` and `(n)`. For `d` orbitals, it gives the DOS seperately for, e.g., :math:`d_{xy}`, :math:`d_{x^2-y^2}`, and so on.
Momentum resolved spectral function (with self energy)
------------------------------------------------------
Momentum resolved spectral function (with real frequency self energy)
---------------------------------------------------------------------
Another quantity of interest is the momentum-resolved spectral function, which can directly be compared to ARPES
experiments. We assume here that we already converted the output of the :program:`dmftproj` program with the