Have you tried linear response? have you performed any convergence test 9especially wrt the number of k points)? SB
On Jul 9, 2008, at 10:48 AM, alan chen wrote: > 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 > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum --- Stefano Baroni - SISSA & DEMOCRITOS National Simulation Center - Trieste http://www.sissa.it/~baroni / [+39] 040 3787 406 (tel) -528 (fax) / stefanobaroni (skype) La morale est une logique de l'action comme la logique est une morale de la pens?e - Jean Piaget Please, if possible, don't send me MS Word or PowerPoint attachments Why? See: http://www.gnu.org/philosophy/no-word-attachments.html -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20080709/a3c75340/attachment.htm
