This is the user forum of the DFT FLAPW code FLEUR. It is meant to be used as a place to asks questions to other users and the developers, to provide feedback and suggestions. The documentation of the code can be found at the FLEUR homepage.
The Fermi energy should actually be written out in the lines following the
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fermi energy and band-weighting factors:
output. If this is not the case it must somehow have gotten lost in the output. But there is another point where it definitly is written out: In the out.xml file.
For hybrid functionals there is a refactoring of the code at the moment. If you use the development version if the code, the PBE0 functional works, with the exception of calculations with multiple atoms in the unit cell that can be mapped onto each other via inversion symmetry. In that case you would have to perform the calculation without making use of inversion symmetry. The HSE06 functional will be functional again in a few months. We have someone working on it at the moment. Also for hybrid functionals calculations you might have to run fleur with the command line option that disables the use of the progress thread lib. ...in case you get a deadlock otherwise.
You compiled Fleur correctly, don't worry. It is just that at runtime it also has to be known where to find the library you want to link to. For this there exists an environment variable LD_LIBRARY_PATH. You have to also put the path for the HDF5 library into that environment variable. If I see it correctly this means that you should invoke a command like
if you are using a bash shell or a z shell. In other terminal shells this will look slightly differently. I suggest to put that line into your .bashrc or .zshrc file if you use one of these shells. With this you don't have to type it in each time before you want to start FLEUR.
Please also note that this visualization is only possible on the basis of the banddos.hdf file, e.g., with the script above. The association of the states with the two spins is encoded in weights. These are not available for the gnuplot script, which is also often used to plot band structures.
To see these results it is not needed to switch on l_noco. Leave it set as "F". If the l_noco switch is set to "T", the calculationSetup/coreElectrons/@ctail switch also has to be set to "F". That is what the error message tells you.
You actually have to do the following things to see the spin-polarization in the band structure:
1. In the inpgen input you have to select a spin-quantization axis, for which you actually expect to see the effect. For the BiTeCl example you wouldn't see anything interesting if this is the z-axis, as it is set in the tutorial. For that case it would be more reasonable to set both angles to 1.570796327=0.5*Pi, i.e., the y-axis. 2. In the fleur input file you have to set jspins to 2, just as you did. 3. When you execute fleur, you obtain a warning because you run a spin-polarized fleur calculation without having a magnetic moment in the setup. Just ignore that warning by invoking fleur with the command-line switch -warn_only.
With the new inpgen input the input generator will find less symmetries in the system, which means that you get more k-points for the calculation. Also in the fleur calculation you have to set up and solve the problem for both spins. These two aspects imply that the calculation will take much longer than in a non-spinpolarized calculation.
I attach for the BiTeCl example inputs for the self-consistent field calculation (inp1.xml) and the band structure calculation (inp2.xml) and a slightly modified python script from the fleur website, adapted to visualize the respective effect (plotBands.py). The attached image bandstructure.png shows the visualization you obtain from this. In cases of degenerate bands it may happen that there are sudden color-changes, because the other band comes to the foreground.
Please note that the band structure plot follows a path from -M over gamma to +M, but both, -M and +M, are denoted as M in the plot.
I hope this clarifies how to obtain the visualization you want to have.
Could you also attach the kpts.xml and sym.xml files? I try to reproduce the problem and have not yet succeeded in doing this. Maybe there is an issue in those files and I just don't see that.
Do you start the calculation with MPI parallelization? If yes, please try it without such parallelization. I think, a few versions ago we had a related force theorem issue that probably yields the error you show.
This is really strange. I actually use a newer Fleur version. Maybe it is an issue with your older version. The inp.xml file validates, so I don't understand why Fleur complains about a "Closing xml element inconsistency". I don't see that.
Besides that your unit cell definition stays wrong. The first idea was that you use the wrong units, but maybe that was the wrong cause. You want to define a two-atom unit cell of an fcc crystal, correct? But such a unit cell does not have the shape of a single-atom fcc unit cell. I think you construct a primitive fcc unit cell, but put two atoms in it.
Just have a look at the MT radii of the Fe atoms. Those are only 1.31 Bohr in your inp.xml file. You can safely assume that every Fe MT sphere with a MT radius below 2.0 Bohr belongs to a pathologic setup.
EDIT: Maybe the XML error is related to the out.xml file. But if there was an error in this older Fleur version it is fixed by now.
EDIT2: I think if you want to have a 2-atom fcc unit cell, the shape would typically be a tetragonal unit cell ('tP'). The lattice parameter 'a' would be the distance between an atom at a corner and the nearest atom at a face center in a conventional fcc unit cell. The lattice parameter 'c' would be the lattice constant of the fcc unit cell.
@sureshravi: I had a look at the inp.xml file you attached. With that I don't obtain an xml inconsistency as you do. But I obtain
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************juDFT-Warning***************** Error message: You lost too much charge Error from PE:0/1 *****************************************
That is probably due to a way too small lattice constant. I guess you specified the unit cell in terms of Angstrom, but you need to define it in Bohr radii.
Are you sure you actually used the correct input files? Could you show me the output of invoking
I made a small test on Fe with probably a bad choice for the lattice constant and surely not converged numerical parameters. ...but with the 3s as core electrons. I attach the input files (as txt files).
Considering the bad parametrization I guess this is okay. ...and you are right. For this calculation the 3s should be described as core electrons.
Please compare your changed input to the one I have attached to see where the differences are. When moving an electron from a valence description to a core electron description one often makes mistakes, because this is related to several changes that have to be consistent.
Of course, this depends on which electrons are treated as core electrons. Could you attach the inp.xml file for which you obtain an error? I will have a look at it.
The hyperfine field feature is part of an alternative relativistic solver that one can use for the core electrons. It is activated by setting calculationSetup/coreElectrons/@kcrel to "T".
The output is kind of hidden. You find it in the out file (not out.xml). An example is this:
(Please note that we have vacation season and it may take a while until an expert is available to answer your question. The version number of the Fleur version determines which expert you need.)
You can always add the -eig hdf command line switch.
Also: I am unsure, but I guess it should be possible to simply combine our Wannier functionality with hybrid functionals calculations (Note that at the moment only PBE0 is working).
I don't know how you created that inp.xml file, but all
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<xi:include
lines are broken. Did you remove / modify them intentionally?
I don't know what files you actually use to start the calculation. If you also have a kpts.xml and sym.xml file you have to add the following to the inp.xml file:
I don't know whether there is more broken in your input. But if something like this is broken I would suggest to actually regenerate the inp.xml file with the input generator. However, you can try out whether adding the lines above helps.
For second variation SOC you are correct. For first variation SOC you have to activate both switches. ...don't forget that you have "numbands" as another convergence parameter in 2nd variation SOC calculations.