topological-insulator-spin-hall

Ab initio calculation of the spin Hall conductivity in topological insulators using Quantum ESPRESSO and Wannier90 codes.

Set paths

The file set-path needs to be modified with the correct paths to the root directories of Quantum ESPRESSO and Wannier90 folders on your machine.

QE_PATH=$HOME/qe-6.4.1              # replace with your quantum espresso path
WANNIER_PATH=$HOME/wannier90-3.0.0  # replace with your wannier90 path 

Troubleshooting

Here is a list of some common problems that might occur during calculations:

1. value of berry_task not recognised in param_read
   The error is still present in the latest release of Wannier90 v3.0.0. To resolve this issue you might need to try the develop branch of the wannier90 repository. There is a related issue on github as well.

2. kmesh_get_bvector: Not enough bvectors found
   This error can be resolved by changing (inreasing) the kmesh_tol in the .win file.

3. Direct lattice mismatch
   This error happens because the real and reciprocal lattice vectors of the .scf file and the .win file do not match.
   I was not able to get a perfect match, so I just commented out the part of code that compares lattice vectors in pw2wannier90.f90 file and recompiled it.

4. too many projections to be used without selecting a subset
   The error seems to go away if you set the projections in the .win file to random as follows.

begin projections
random
end projections

There is also a related thread on Wannier mail list.