Dear Kirill,

The first part of my answer is about the reciprocal Bravais matrix. This is actually written out to the out file by the input generator. But it is overwritten once you perform a Fleur calculation. For example for Si inpgen out has a section that looks like

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Bravais lattice vectors

0.000000 5.130609 5.130609

5.130609 0.000000 5.130609

5.130609 5.130609 0.000000

reciprocal lattice vectors

-0.612324 0.612324 0.612324

0.612324 -0.612324 0.612324

0.612324 0.612324 -0.612324

Be careful to interpret these matrices in the correct way. There may be a transposition present.

The second part is about the calculation of the cartesian coordinates of the k points:

We calculate the band band structure path in cartesian coordinates in the file dos/types_eigdos.F90 within the fleur source code folder. It is this loop:

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kx(1) = 0.0

vkr_prev=matmul(kpts%bk(:,1),cell%bmat)

DO k = 2, kpts%nkpt

vkr=matmul(kpts%bk(:,k),cell%bmat)

kx(k)=kx(k-1)+ sqrt(dot_product(vkr-vkr_prev,vkr-vkr_prev))

vkr_prev=vkr

ENDDO

kx is the x coordinate along the bandstructure plot. vkr is the cartesian coordinate of the respective k point stored in kpts%bk. cell%bmat is the reciprocal Bravais matrix though I am not sure whether the factor 2*pi is in it.

About compiling and linking to HDF5 I would like to add that (a) it is important to compile HDF5 with the same compiler you use for Fleur, (b) on my machine I use the following configure line for HDF5:

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FC=/usr/local/intel/impi/2019.3.199/intel64/bin/mpiifort CC=/usr/local/intel/impi/2019.3.199/intel64/bin/mpiicc CXX=/usr/local/intel/impi/2019.3.199/intel64/bin/mpiicpc ./configure --enable-fortran --enable-parallel

Of course your compilers differ, but one important point here is the --enable-fortran switch. (c) You need to specify the HDF5 library path in your LD_LIBRARY_PATH environment variable. For me this looks like

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export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:~/hdf5/current/hdf5/lib

Of course, for you this is a different path.