[Pw_forum] high-frequency dielectric constant of SrTiO3

[alan chen]

Dear PWSCF users,
      I am calculating the high-frequency dielectric constant of SrTiO3.
Using the method given in the example31, I calculate D[E=0.001a.u.] and
D[E=0] and eps_inf=4*pi*(D[E=0.001a.u.]-D[E=0])/(0.001a.u.*Omega) + 1 where
Omega is the volume of the unit cell.
      I sample the Brillouin zone by 4x4x8 (uniformly distributed) and
obtain: D[E=0.001 a.u.] = 0.155 and D[E=0] is almost zero, therefore
eps_inf=6.0 which is much smaller than experimental values.
      Did I do the calculation correctly? Does anyone have experience about
calculating high-frequency dielectric constant of SrTiO3?
      Thank you very much.

Hanghui
Department of Physics,
Yale University
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