[Wannier] Using kmesh.pl utility

[Jonathan Yates]

On 16 Mar 2010, at 15:15, Elie Moujaes wrote:

> Dear all and Prof. Yates,
>
> Thanks for your reply. I have a small question about using the .PL  
> file..How can I make it produce the suitable k-mesh. I used that of  
> the example of graphite but when i executed pw2wannier90.x  (I used  
> disentanglement and everything went smoothly when wannier90.x was  
> applied) I got the error
>
>
> Checking info from wannier.nnkp file
>
>   Something wrong!
>   rlatt(i,j) = 0.9999919712663213  at(i,j)= 1.
>
> I think this might be related to to the wrong kmesh.

That error message does not arise from a problem with the k-points.

  pw2wannier90 is telling you that the lattice vectors in the win file  
are different to those in the pwscf input.
   They are only slightly different (0.9999919712663213 vs 1.0 in  
units of alat) - so I suspect you just need to give a few more decimal  
places in the win and/or nscf file.

  If you are still confused - post the appropriate parts of the win  
and pwscf input files.

Below I've given the example of generating a k-point mesh of 4x2x1  
first for pwscf, then for the win file:

[pc8] utility > ./kmesh.pl 4 2 1
K_POINTS crystal
8
   0.00000000  0.00000000  0.00000000  1.250000e-01
   0.00000000  0.50000000  0.00000000  1.250000e-01
   0.25000000  0.00000000  0.00000000  1.250000e-01
   0.25000000  0.50000000  0.00000000  1.250000e-01
   0.50000000  0.00000000  0.00000000  1.250000e-01
   0.50000000  0.50000000  0.00000000  1.250000e-01
   0.75000000  0.00000000  0.00000000  1.250000e-01
   0.75000000  0.50000000  0.00000000  1.250000e-01

[pc8] utility > ./kmesh.pl 4 2 1 w
   0.00000000  0.00000000  0.00000000
   0.00000000  0.50000000  0.00000000
   0.25000000  0.00000000  0.00000000
   0.25000000  0.50000000  0.00000000
   0.50000000  0.00000000  0.00000000
   0.50000000  0.50000000  0.00000000
   0.75000000  0.00000000  0.00000000
   0.75000000  0.50000000  0.00000000


  Jonathan





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