[Pw_forum] Information about Hamiltonian matrix

[marzari at MIT.EDU]

Dear Min,


what Paolo means here is the Hamiltonian in a plane wave basis.
Of course, all codes give you the Hamiltonian in the basis of the
eigenvectors (since these are the eigenvalues) and both Wannier90
and WanT give you the Hamiltonian in a MLWFs basis; this latter has
the advantage of being localized (hence the Hamiltonian is sparse and 
diagonally
dominanant), and minimal but exact (e.g. for Si you only need
4 MLWFs to describe exactly the whole valence band manifold).

Happy new year,

              maximally-delocalized nicola


Quoting Paolo Giannozzi <giannozz at nest.sns.it>:

> On Wednesday 02 January 2008 01:13, Min Seung Kyu wrote:
>
>> Can I obtain hamiltonian matrix in PWSCF?
>
> not in PWscf nor in any other plane-wave based code designed for
> serious usage. All you can have is the result, H\psi, of the application
> of the hamiltonian H operator on a vector \psi. This is done in routine
> PW/h_psi.f90
>
> P.