[Wannier] Fourier Coefficients of a Wannier Function

[Arash Mostofi]

Dear Fawei,

The answer to your question is yes, but in a slightly limited sense. 
Depending on exactly what you want to do it may be either very easy or 
more tricky to adapt what is already coded.

Currently what is implemented in the PWscf interface to Wannier90 is as 
follows:

+ For Gamma-point only Brillouin zone sampling, you can get the 
PWscf-Wannier90 interface programme pw2wannier90 to write out the first 
32 Fourier coefficients of the wavefunctions in reciprocal space (ie, 
u_n(G) at the 32 G-vectors with smallest |G|) to a file called 
seedname.unkg. This behaviour is activated by keyword called 
"write_unkg" in the input file for pw2wannier90.

+ Once you have these Fourier coefficients and you have found the 
unitary transformation that gives you MLWFs, you can then easily 
determine the first 32 Fourier coefficients of the MLWFs.

+ The context in which we did this sort of thing was transport 
calculations and is described in M. Shelley et al, Comput. Phys. Commun. 
182, 2174 (2011) [http://dx.doi.org/10.1016/j.cpc.2011.05.017 or, if you 
don't have access to the online journal, 
http://www.cmth.ph.ic.ac.uk/people/a.mostofi/papers/ms_mlwftran.pdf]; in 
particular, see the Appendix of the paper and, eg, subroutine 
tran_find_integral_signatures in transport.F90 in the current most 
recent version of Wannier90 (v1.2).

Hope this helps.

Arash

--
Dr Arash A Mostofi
Departments of Materials and Physics
Deputy Director, CDT on Theory and Simulation of Materials
Imperial College London, London SW7 2AZ, UK
+44 (0)207 594 8154 | www.cmth.ph.ic.ac.uk/people/a.mostofi

On 20/05/2012 06:38, 郑法伟2063 wrote:
> Dear Wannier90 developers and users,
>
> Is it possible to get the Fourier coefficients or Bloch wave
> coefficients of a wannier function from the Wanner90 output files
> directly ?
>
> Thanks,
> Fawei
>
>
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