ferroelectric calculation

[bakgenc]

I am performing ferroelectric calculations for Sb-doped Bi2Te3, a topological insulator with an energy gap of approximately 70 meV, using VASP.
should I use LDA or GGA?

[manuel_engel1]

Hi,

Thanks for reaching out. Both LDA and GGA are approximations that can sometimes yield physically inaccurate results, especially when it comes to the band gap. It's a priori quite difficult to say which approximation will give good results in a particular system. Therefore, I encourage you to experiment with LDA/GGA and maybe even some other flavors like PBEsol to find out what best describes your system and the physics you are interested in.

I will move this topic over to From Users to Users. Maybe someone else who already has experience with Bi2Te3 can contribute to this question.