Dear, it is possible to calculate the energy dependent dielectric function at q=0 by using the optical flag in the input.fdf Then the static dielectric constant is given by the real part of the dielectric function at zero energy. This method suffer of the RPA+dipole approximation, so it is not exact.
RG On 08 December 2012, Sergio Ferrari <[email protected]> wrote: > I am not an expert, but in my humble opinion there is no way (up to today) > to calculate ab-initio the dielectic constant of a material. Please any > other physicist expert in this area correct me if I am wrong. > > 2012/12/8 郭振东 <[email protected]> > > > Dear Siesta User > > Can we use SIESTA to calculate the dielectric constant of the material > > such as BN ? > > Best regards > > Zhendong > > > > > > > > >
