First-Principles Study of Three-Dimensional Electrides Containing One-Dimensional [Ba 3 N] 3+ Chains.

Electrides, a unique type of compound where electrons act as anions, have a high electron mobility and a low work function, which makes them promising for applications in electronic devices and high-performance catalysts. The discovery of novel electrides and the expansion of the electride family have great significance for their promising applications. Herein, we reported four three-dimensional (3D) electrides by coupling crystal structure database searches and first-principles electronic structure analysis. Subnitrides (Ba 3 N, LiBa 3 N, NaBa 3 N, and Na 5 Ba 3 N) containing one-dimensional (1D) [Ba 3 N] 3+ chains are identified as 3D electrides for the first time. The anionic electrons are confined in the 3D interstitial space of Ba 3 N, LiBa 3 N, NaBa 3 N, and Na 5 Ba 3 N. Interestingly, with the increase of Na content, the excess electrons of Na 5 Ba 3 N play two roles of metallic bonding and anionic electrons. Therefore, the subnitrides containing 1D [Ba 3 N] 3+ chains can be regarded as a new family of 3D electrides, where anionic electrons reside in the 3D interstitial spaces and provide a conduction path. These materials not only are experimentally synthesizable 3D electrides but also are promising to be exfoliated into advanced 1D nanowire materials. Furthermore, our work suggests a discovery strategy of novel electrides based on one parent framework like [Ba 3 N] 3+ chains, which would accelerate the mining of electrides from the crystal structure database.