[Pw_forum] Fwd: Error when using wannier_ham.x for graphene

[Sclauzero Gabriele]

I
 guess that, as for wannier90, you need to provide Bloch states and eigenvalues on a regular grid covering the full Brillouin Zone, not only the irreducible wedge.
Practically speaking, try to perform a nscf calculation using nosym=.TRUE. before using wannier_ham.
You might need to specify manually the set of k-points, in order to avoid that the k-point set gets reduced by symmetry.
For 10x10x10 mesh in a 3d system, I would use something like:

K_POINTS crystal
1000
0.0 0.0 0.1 0.001
0.0 0.0 0.2 0.001
...
0.0 0.0 0.9 0.001
0.0 0.1 0.1 0.001
...
0.0 0.1 0.9 0.001
...
0.9 0.9 0.9 0.001

You can easily generate something more appropriate to your system through a small script.
If you feel lazy, then give a try to kpoints.x in PW/tools.

HTH

GS



Hi Everybody,


I try to use "wannier_ham.x" to generate a model Hamiltonian of graphene. The available example (PP/examples/WannierHam_example)
 runs well, but the graphene case fails. After scf and nscf calculations, one problem occurs always during the third step :

                                                 WARNING: k-points set is in the irreducible brillouin zone.

                                                                 Wannier energies and occupations are wrong!
 Atomic wfc used for LDA+U Projector are orthogonalized
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
     Error in routine wannier_proj (1):
     wrong orthogonalization on k-point
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
     stopping ...
My wannier_hamilt.in<http://wannier_hamilt.in/> shows here:
&inputpp
 prefix='graphene'
 outdir='./'
 nwan =2
plot_bands=.true.
/
WANNIER_AC
 Wannier# 1 4  5
 atom 1
 p 3 1.0
 Wannier# 2 4  5
 atom 2
 p 3 1.0
/
The related scf and nscf  files are also attached, anybody can give me some suggestions?

Wayne, Yan
Division of Physics and Applied Physics
School of Physical and Mathematical Sciences
Nanyang Technological University, Singapore
yanjiaxu at gmail.com<mailto:yanjiaxu at gmail.com>


2014-04-25 19:28 GMT+08:00 jiaxu yan <yanjiaxu at gmail.com<mailto:yanjiaxu at gmail.com>>:
Hi Everybody,


I try to use "wannier_ham.x" to generate a model Hamiltonian of graphene. The available example (PP/examples/WannierHam_example)
 runs well, but the graphene case fails. After scf and nscf calculations, one problem occurs always during the third step :

                                                 WARNING: k-points set is in the irreducible brillouin zone.

                                                                 Wannier energies and occupations are wrong!
 Atomic wfc used for LDA+U Projector are orthogonalized
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
     Error in routine wannier_proj (1):
     wrong orthogonalization on k-point
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
     stopping ...
My wannier_hamilt.in<http://wannier_hamilt.in/> shows here:
&inputpp
 prefix='graphene'
 outdir='./'
 nwan =2
plot_bands=.true.
/
WANNIER_AC
 Wannier# 1 4  5
 atom 1
 p 3 1.0
 Wannier# 2 4  5
 atom 2
 p 3 1.0
/
The related scf and nscf  files are also attached, anybody can give me some suggestions?

Wayne, Yan
Division of Physics and Applied Physics
School of Physical and Mathematical Sciences
Nanyang Technological University, Singapore
yanjiaxu at gmail.com<mailto:yanjiaxu at gmail.com>

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Dr. Gabriele Sclauzero
Materials Theory - ETHZ
ETH Zurich, HIT G 43.2
Wolfgang-Pauli-Str. 27
8093 Zürich, Switzerland

Phone +41 44 633 94 10
Fax +41 44 633 14 59
gabriele.sclauzero at mat.ethz.ch<mailto:gabriele.sclauzero at mat.ethz.ch>
www.theory.mat.ethz.ch