Figure 7 . (a) The selectivity of eNRR and HER for ten kinds of selected candidates. (b)-(f) AIMD simulations for Mn2@site1, Co2@site2, Os2@site3, V2@site4, and Cr2@site4 lasting for 9000 fs, the insert figures are the after-simulated structures of Mn2@site1, Co2@site2, Os2@site3, V2@site4, and Cr2@site4, respectively.