[Pw_forum] A question about constructing model hamiltonian using PWSCF

[Nicola Marzari]

Maybe an email for the wannier list. But, in short - the more localized
your orbitals the better the interpolation. In simple cases like
III-V semiconductors is very simple to construct orbitals (e.g. using 
Lowdin)
that are close to optimal - in many other cases it is not.

			nicola



On 21/09/2015 10:34, 庞瑞(PANG Rui) wrote:
> Dear all
> It is popular recent years that using wannier function to construct a
> tight binding model. But recently in a textbook(Fundamentals of
> Semiconductors,Peter Y. Yu, Manuel Cardona,Springer,2010), I found that
> they proposed to do the same job. I tried to transform the KS
> hamiltionian of graphene back to atomic orbital representation with the
> transform matrix provided by projwfc.x, found it gave a reasonable
> result, at least the pz-pz hopping is 2.8 eV, quite close to the value
> in wannier representation. So my question is what is the drawback of
> using Lowdin orbitals so that everyone use wannier function? Or is there
> any misundertanding of me in using these conception?
> Welcome for any suggestion.
> Sincerely
> PangRui
>
>
>
>
> ------------------
>
>
>         庞瑞(PANG Rui)
>
> South University of Science and Technology of China/Department of Physics
>
> No.1088,Xueyuan Road, Shenzhen,Guangdong
>
>
>
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-- 
----------------------------------------------------------------------
Prof Nicola Marzari, Chair of Theory and Simulation of Materials, EPFL
Director, National Centre for Competence in Research NCCR MARVEL, EPFL
http://theossrv1.epfl.ch/Main/Contact http://nccr-marvel.ch/en/project