Computational mining of endohedral C 70 electrides: tri-metal alkali and alkaline-earth encapsulation.

C 70 is the second most abundant fullerene next to C 60 . In this work, the exploration of C 70 based electrides is proposed by theoretical encapsulation of group I/II trimetallic clusters into the C 70 cage. Herein, we provide computational evidence that endohedral metallofullerenes M 3 @C 70 (M = Li, Na, K, Be, Mg, Ca, Sr, Ba) can exist stably by calculating encapsulation energies and analyzing atom centered density matrix propagation molecular dynamics simulations. According to the results of the atoms in molecules analysis, electron localization functions and nonlinear optical properties, M 3 @C 70 (M = Li, Be, Mg, Ca) fullerenes are identified as electrides. Interestingly, Li 3 @C 70 and Be 3 @C 70 are the systems with better electride performances among alkali metal and alkaline earth metal systems, respectively. It is worth noting that C 70 can improve the polarizability and first hyperpolarizability of electrides compared with C 60 . Our work unearths the potential of M 3 @C 70 electride systems and paves the way for the research of C 70 -based electrides.