“…Ultracold molecules are mostly prepared by photoassociation (PA) [7] and magnetoassociation (MA) [8]. Recently, the research of ultracold diatomic molecules has been extended from alkali metal atom systems, such as homonuclear Cs 2 [9], Rb 2 [10,11], Li 2 [12,13] and heteronuclear LiCs [14,15], LiRb [16,17], RbCs [18,19], NaRb [20], NaK [21], KRb [22] to alkaline earth metal atom systems and rare earth metal atom systems, such as Sr 2 [23], CsYb [24], and Eu 2 [25]. In * Author to whom any correspondence should be addressed.…”