[Wannier] how to calculate fermi surface with VASP and WANNIER90

[Jonathan Yates]

On 29 Jan 2014, at 10:24, 刘仕晨 wrote:

> Dear All:
> 
>     I've just started to use the wannier90 code, and having a little problem. so, I would appreciate very much if you could give me a little bit of suggestions.
>     I want to know how to calculate fermi surface with VASP and WANNIER90, I failed to get a good result for some metals.

Shi-Chen,

 You've not given us much information here - how do you decide what is good result, and which metals fail?

Anyhow, let me make some generic comments:
 In order for the wannier interpolation, and hence Fermi surface calculation, to work well you need to have "good" (ie well localised) wannier functions.
  - Are your WF real?
  - Do the wannier interpolated bands match well the VASP bands in the region of interest?
 If these conditions are not satisfied, you should not expect to get a meaningful fermi surface.

  In the wannier tutorial there are examples for Copper and Iron - these are written for pwscf, but they could be easily adapted for vasp.
 Finally, I note that you are using a 20 20 20 MP grid to generate the Wannier functions - this is likely to be far more than is needed for converged results (not a problem, just makes the calculations a lot slower). You might find it easier to start with a pretty small grid (eg 4x4x4) to get things working, then move up to a larger grid to converge the results to the accuracy you require.

 Jonathan








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