On Tuesday 10 January 2006 16:36, Andrea Ferretti wrote: > my question is about non-self consistent calculations: > what I expected is that no symmetrization should be performed > (e.g. when I compute band structure for silicon along a specific > symmetry line it makes no sense to me to define weights and so on...).
it is not that simple: there are cases in which you may want a grid in the IBZ, such as for instance to calculate the DOS, or phonons at a finite q-vector. Presently the number of input k-points is left unchanged if there is no evidence of further processing, such as tetrahedron, gaussian broadening, q-vector for phonons etc, in the input data for the nonscf run > therefore I guess that nosym = .TRUE. should be effectiveless 'effective' or 'effectless'? nosym=.true. does not do what its name would suggest, i.e. increase the number of k-points because symmetry is not used; it actually prevents the increase of the number of k-points with reduced symmetry. It does, or should do, what is explicitly stated in the INPUT_PW file. I am quite dissatisfied with the present implementation of the k-point+symmetry stuff: it is a stratification of different approaches, and it shows. If you want to try to disentangle this mess, PW/setup.f90 is the place to start from 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
