Hi Quansheng,
Thank you so much for your reply. If we are interested in the sum of berry curvature in occupied states(for example,to calculate the anomalous hall conductivity) it is only the trace of the matrix that we care about. But I’m interested in the berry curvature of each state around the fermi level . So I should do my calculations in Hamiltonian gauge, using the subroutine berry_curvature_singlek_EF ,perhaps with some modification.
Best