This bug was mistakenly introduced during ithe porting of DFPT+U
from QE 5.0.2 to the latest QE. Interestingly, this stupid bug
was found only when computing phononsi+U for bulk Fe using
Fe.pbe-spn-rrkjus_psl.0.2.1.UPF (the bug did not show up when using
e.g. fe_pbe_v1.5.uspp.F.UPF). The benchmark was done with the
frozen phonon approach using phonopy. Moreover, in other tests
(for bulk Si, Al, Ni) this bug also did not show up.
1) DFPT+U with ortho-atomic orbitals is disables,
because it is more complicated than it was expected.
First, Hubbard forces in pw.x must be extended to ortho-atomic orbitals
and then DFPT+U must be reconsidered.
2) Update the reference files for example18 for DFPT+U
3) Various minor changes
phonon code to prevent execution in non-implemented cases (NOT YET WORKING
because variables lxdm and dft_d3 are not properly set when file is read!);
removal of unused variables
I. Timrov, B. Himmetoglu, N. Marzari, M. Cococcioni). The code was ported
from QE 5.0.2 to the latest version of QE, by I. Timrov with the help of
A. Floris and M. Cococcioni. Many thanks for the discussions with P. Giannozzi,
P. Delugas, A. Dal Corso, M. Calandra, L. Paulatto about various issues
during the porting. Sorry if I forgot to mention someone.
2) Some small modifications in the HP code in order to be consistent
with the porting of PHonon+U and changes in LR_Modules.
uneeded relinking; the mysterious "tldeps" machinery modified accordingly;
added explicit dependencies to GWW targets to prevent (once again) problems
with make -j (seems to work now). make.depend updated (once again).
impossible clashes with LIBS as defined by the OS or as used by the configure's
of external libraries (e.g. FoX, for which one such problem has been reported)
Explaintion:
The Wigner-Seitz construction in EPW was done by constructing a cell
centred unit cell. This is fine for electronic properties (this is what is done in wannier90).
However for phonon or electron-phonon properties, one can have issues when the cell
is tilded for example.
The proper way is to construct a set of WS vectors centred on pairs of atoms (phonons)
or atoms (el-ph).
In the matdyn code, a FT grid is constructed with weigths centred on pairs of atoms
and zeros everywhere else.
EPW now reproduced exactly the results of matdyn for the interpolated phonons at a
lower computation cost. Indeed we minimize the number of zeros by keeping the union
of values between all the cells.
In both cases this is very fast anyway but is important for el-ph properties.
A Wigner module was created to deal with this.
In addition, the subroutine cdiagh2 from PHonon/PH/rigid.f90 has been made public to
avoid code duplication in EPW
functions
in case the starting computation has been done twfcollect=.true.
run_nscf saves the wave functions in tmp_dir_phq and not in tmp_dir.
We have to find a way to have them in the same place in both cases.
Not now because release is tomorrow (29 june 2018).
Dirty fix if open_buffer fails in tmp_dir go back to tmp_dir_phq and try
again.
Since github and gitlab just distribute a snapshot of the git repository,
these files must be in the repository as well. NOTA BENE:
All changes MUST GO TO *.tex or *.def FILES, NOT to these files!
Also note that the "make doc" machinery produces also *.xml files and
latex2html converted html versions of latex files. I don't think they belong
to the repository (latex files should maybe be replaced by md files)
Paolo Giannozzi