“…[5] On the one hand, much effort has been done to the HHG of the symmetric molecules, such as N 2 , [6,7] H + 2 , [8][9][10] and CO 2 . [11] On the other hand, the investigation of the asymmetric molecule also attracts a great deal of attention, such as CO, [12] HCl, [13] HeH 2+ , [14,15] which have the permanent dipole of the molecule (PDM) and the multiple centers because of the symmetry breaking.…”