[Wannier] ERROR in hamiltonian_wigner_seitz

[Jonathan Yates]

On 26 Nov 2010, at 09:11, Carmine Autieri wrote:

> Dear Wannier users, 
> 
> I am a Phd student and I am new on this forum. 
> I am studying Sr2RuO4 and Sr3Ru2O7 and I want to calculate accurately hopping in the direction 100 and 010.
> When I study Sr3Ru2O7 all is ok.
> When I study Sr2RuO4, I find a problem for mpgrid = 8 8 2 or 10 10 4, but all is ok if I use
> the same number of k-points in all directions (mpgrid = 6 6 6 or 4 4 4). I change only the grid of k-points. 
> 
> 
> I get the following error as written to case.wout file for mpgrid= 8 8 2
> 103 lattice points in Wigner-Seitz supercell:

Carmine,

 That routine is looping over a supercell of the unitcell to try to find all of the points in the Wigner-Seitz cell. The size of the search supercell is hardwired. I had thought the values were sufficient to catch most physical cases (at least no one had reported a problem in the past few years) however, I'm guessing that your cell and kpoint mesh requires a bigger search supercell.
 I think I will modify the code to use a keyword to set the search supercell. Then if the routine fails to find all of the points it can suggest increasing the parameter. (it could do this automatically..)
 If you like a challenge, modify hamiltonian_wigner_seitz yourself. Otherwise I will do it in the next few days.
 In either case I'd be interested in the *.win file - to know that we have fixed the issue, and also to make sure what I have described really is the problem.


 Jonathan





-- 
Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK
tel: +44 (0)1865 612797                http://users.ox.ac.uk/~oums0549/