Dear everyone, In the last but one email, there are some mistakes in my expression. >>I have generated q-points via PW/kpoint_grid.f90 and I'm testing it >>using 3.2 version. I just used 3.2 version, it generates qpoints automatically through ph.x, not via PW/kpoint_grid.f90. I'm sorry for misleading you. Good luck! Guoying