Hi David,
Thank you for the nice explanation and suggestions. I tried to increase
the mesh spacing, but the problem still persists. The time-dependent
observable that I calculate should according to symmetry be 60-degree
periodic in ZnO , but there is a small error. I also tried using
symmetr
Lun Yue,
As far as the implementation is concerned, I hope some of my
collaborators who are closer to the code will answer you.
My feeling is that, once the Hermiticity is enforced, you are
just dealing with the intrinsic presence of the mesh
discretization error, and if this error is a problem
Dear all,
I am writing a real-time propagation code that requires high accuracy of
the the Berry connection matrix A_{nm}(k) = i in the
Hamiltonian gauge, which is e.g. given in WYSV2006 Eq.(25) and depends
on A in the Wannier gauge. However, in the calculation of the Berry
connection matrix
