Hello, noone of the developers is interested in such a fundamental issue? It may be a bug...
RG On Mon 07 Mar 2011, you wrote: > Dear all, > > I repeated the calculation using a 2x2x2 grid (input file attached). The > result is the same. This is not surprising, since the problem is not > related, in my opinion, to the calculation accuracy (also, the > calculation at the gamma point should be reasonable for an amorphous > system). > > I verified that the Fermi energy lies inside the gap (bands attached). > > The epsimg is larger than zero at E<Egap. That's not possible. > > > Roberto > > In date 5/3/11 23:52:32, Alexander Vozny wrote: > > Roberto, > > are you sure your Fermi level is in the gap? > > If yes, then I would agree with Karim that most likely your k-grid for > > DOS is different from k-grid for optical calculation. > > Alexander. > > In date 4/3/11 18:40:44, karim rezouali wrote: > > Roberto, > > > > The band structure appears not to be totally correct. Seeing your > > input file systlab.fdf, I realized that this curve is obtained under > > the gamma point.approximation > > > > Try to sample the Brillouin zone as follows: > > %block kgrid_Monkhorst_Pack > > 2 0 0 0.0 > > 0 2 0 0.0 > > 0 0 2 0.0 > > %endblock kgrid_Monkhorst_Pack > > > > > > Optical calculations: > > > > %block Optical.Mesh > > > > 2 2 2 > > > > %endblock Optical.Mesh > > > > These changes will make the calculation slightly heavier but that's > > the price to pay for something more accurate.
