[Wannier] something wrong!! rlattice =0.9999999 at (i,j)=1

[Jonathan Yates]

On 16 Mar 2010, at 17:56, Elie Moujaes wrote:

> I am really thankful for your help. kmesh is very cool to use. I tried correcting the number of digits in the win file but it did not solve my erro.. actually in my scf, I do not define lattice vectors. Only atom positions are involved (because ibrav=4.0) and the output scf and .nscf files give the lattice vectors which i have used in my WIN calculation? 
>  
>      crystal axes: (cart. coord. in units of a_0)
>                a(1) = (  1.000000  0.000000  0.000000 )  
>                a(2) = ( -0.500000  0.866025  0.000000 )  
>                a(3) = (  0.000000  0.000000  4.536660 )  
> (a0=4.6087 a.u)

Elie,

 The problem is that pwscf only writes out a0 to 4dp. In the pwscf input file you defined it as celldm(1) =4.608737
pw2wannier90 checks that the cell vectors in pw and wannier90 agree to 6dp.
 So you need to use the value of a0 that you actually specified in the pwscf input.

A quick calculation suggests that this would be the appropriate cell for the win file:

 4.608737    0.0000000 0.000000
-2.3043685   3.9912833 0.000000
0.0000000    0.0000000 20.90827280

[at one point I intended to write a script to automatically generate the cell and lattice positions from the pwscf input - thus avoiding these conversion issues. If anyone has such a script, or would like to write one, do let me know..]

 Jonathan




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