Re: Z2 invariant calculation ( No.1 ) 
 Date: 2022/10/17 23:52
 Name: Naoya Yamaguchi
 Hi,
>I saw the Z2FH.C code and it seems any exp(iG.r) coefficients did not consider in the Kramarspair or Timereversal subroutines included in this code!
All the treatments are addressed as appropriate, and the implementation of `Z2FH` is based on http://dx.doi.org/10.1016/j.cpc.2012.04.001 . Please refer to the above article to find which code corresponds to each treatment.
Regards, Naoya Yamaguchi

Re: Z2 invariant calculation ( No.2 ) 
 Date: 2022/10/18 03:25
 Name: Alireza Baradaran <alireza.baradaran@gmail.com>
 Thank you Dr Yamaguchi
Do you help me to know how the link variable defined by Dr. Fukui and Hatsugai derived? I can't find any reference.

Re: Z2 invariant calculation ( No.3 ) 
 Date: 2022/10/18 12:49
 Name: Naoya Yamaguchi
 Dear Alireza Baradaran,
In `Z2FH`, u, the periodic part of a Bloch orbital psi, does not appear explicitly, and instead, psi appears. Transformation from u to psi is necessary to compare the actual implementation with equations in the article.
Regards, Naoya Yamaguchi

Re: Z2 invariant calculation ( No.4 ) 
 Date: 2022/10/18 20:23
 Name: Alireza Baradaran <alireza.baradaran@gmail.com>
 Dear Dr. Yamaguchi,
This means that if we have diagonalized the Hamiltonian using the tightbinding method so that its output is eigenvectors, which are the periodic part of the wave function, we should include these eigenvectors in the definition of the link variable. This is right?
Regards, Alireza Baradaran

Re: Z2 invariant calculation ( No.5 ) 
 Date: 2022/10/19 15:10
 Name: Naoya Yamaguchi
 Dear Alireza Baradaran,
What I mentioned is that the link variable can be obtained from u or psi. In the OpenMX code, the overlap matrix between u at two adjacent kpoints is evaluated with Eq. 11 in http://www.openmxsquare.org/tech_notes/tech111_1.pdf .
Regards, Naoya Yamaguchi
