| Re: Topological invariant calculation for large system with only gamma kpoint ( No.1 )|
- Date: 2020/07/27 11:10
- Name: Hikaru Sawahata <firstname.lastname@example.org>
- Hi Frank,
Is this a Z2 invariant? Or Chern number? Or others?
>The topological features
My opinion is we cannot calculate the topological invariant in most cases only Gamma point.
However, only Z2 topological invariant cases, we may be able to compute it by low computational cost.
Z2 invariant of the system with inversion symmetry can be evaluated by parity signs on time reversal invariant k-points.
Please see this article.
| Re: Topological invariant calculation for large system with only gamma kpoint ( No.2 )|
- Date: 2020/07/27 11:46
- Name: Fumiyuki Ishii
- Hi Frank
After computing SCF calculation by Gamma point, you can compute topological invariants by increasing k-point in post processing code of computing Z2 or Chern number.
Please check k-point convergence for not SCF but post processing code.