[Pw_forum] about output wavefunction, charge density and potential

[Paolo Giannozzi]

On Saturday 01 April 2006 05:10, J G Che wrote:

> I find that in each iterative, wavefunction, potential and charge density
> will be saved on disk. Who knows how to output these once only when 
> the self-consistent is reached. Thanks!

- if you have more than one k-point per processor, you have to save
  wavefunctions to disk. It would be possible to store them into memory 
  but it would require extensive changes to the code (and a lot of memory)
- if you have just one k-point and do not specify disk_io='high' the
  code will write wavefunctions only at convergence
- the charge density and potential are written at each scf step.
  This is a behavior that could be changed with simple modifications
  in the code. These arrays however are usually much smaller than
  the wavefunctions.
- unless you specify disk_io='high', auxiliary arrays used for
  self-consistency are not written to disk but stored
- other files are typically small

Paolo
-- 
Paolo Giannozzi             e-mail:  giannozz at nest.sns.it
Scuola Normale Superiore    Phone:   +39/050-509876, Fax:-563513 
Piazza dei Cavalieri 7      I-56126 Pisa, Italy