Hi Andrei, I plotted only few bands at the band-edges: there was so many bands that the gap was barely visible, so I had to zoom the plot to measure it.
In attachment the DOS plotted around the Fermi energy. R In date 4/3/11 16:00:14, [email protected] wrote: > > Indirect (band structure attached) > > > > R > > Roberto: > sorry for this question, but are you sure that this band structure > corresponds to your 64-at calculation? I'd expect much more bands > and much less dispersion with 64 at. supercell. > (I did not count the bands per energy interval, though, > so I might be wrong). > Anyway: how does your total DOS look like? > > Best regards > > Andrei Postnikov > > > In date 4/3/11 15:23:46, karim rezouali wrote: > >> Dear, > >> > >> Is the material under study (ie, bulk amorphous silicon) has a direct > >> electronic gap or not? > >> > >> Karim > >> > >> > >> Hello, > >> > >> I calculated the band structure of bulk amorphous silicon (64 atoms > >> tetrahedrically coordinated). I found an HOMO-LUMO band gap of about 0.7 > >> eV. Then I performed the OpticalCalculation, but I have that the > >> resulting > >> imaginary dielectric function has a peak at E<0.7. How is this possible? > >> I > >> expect that each valence-to-conduction transition must be larger than > >> the > >> bang-gap! > >> > >> Roberto
<<attachment: a-Si_DOS.png>>
