text: hamiltonian and overlap from python
  I am working on a small project for which I would require H(k) and S(k) from a SIESTA run (not TRANSIESTA).
  I was wondering which would be the most straightforward way to do this with with already existing solutions.
  I have found both ASE and sisl but I am not quite sure if either of them have the capability to extract H(k) and S(k) from a HSX or an nc file. Could someone point me to a short example how this can be done it it is possible at all ?
  Also due to the nature of the problem I am working on any solution should work for spin non-collinear systems.
  Question information
  - Language:
  - English Edit question
  - Status:
  - Answered
  - For:
  - Siesta Edit question
  - Assignee:
  - No assignee Edit question
  - Last query:
  - 2017-06-17
  - Last reply:
  - 2017-06-18
  Does this also return overlaps ?
  Looking at the github repo this was not obvious for me.
  Should I transfer my questions about sisl to github ?
  Yes, the *.nc file also contains the overlap matrix, so both can be created.
  Generally, you should ask sisl questions on github.
  sisl should be able to do this once you have generated the *.nc file.
  Simply do something like this
  <<<
  import sisl
  H = sisl.get_
  sile('syslabel. nc').read_ hamiltonian( )
  H.Hk(k=[0.5, 0.5, 0.5])
  <<<
  Which returns the Hamiltonian at k edge of the Brillouinzone.
  Note that the stored Hamiltonian in the *.nc file (and HSX for that matter) is the real-space Hamiltonian and H(k) can easily be generated from this.