A theoretical study on superalkali-doped nanocages: unique inorganic electrides with high stability, deep-ultraviolet transparency, and a considerable nonlinear optical response

By doping an Al 12 N 12 nanocage with superalkali Li 3 O, a series of Li 3 O@Al 12 N 12 compounds were theoretically designed and investigated for the first time. Computational results reveal that these species contain diffuse excess electrons, and thus can be regarded as inorganic electrides of a new type. As expected, these proposed electrides possess considerable first hyperpolarizabilities ( β 0 ) up to 1.86 × 10 7 au. In particular, the lowest-energy Li 3 O@Al 12 N 12 exhibits high stability and excellent deep-ultraviolet transparency. Moreover, the effects of superalkali and nanocage subunits on the NLO responses of M 3 O@Al 12 N 12 (M = Li, Na, K) and Li 3 O@X 12 Y 12 (X = B, Al; Y = N, P) are systemically investigated. Results show that the respective substitution of Na 3 O and B 12 P 12 for Li 3 O and Al 12 N 12 can bring a larger β 0 for such electrides. This study may be significant in terms of providing an effective strategy to design thermally stable inorganic electrides as potential high-performance NLO molecules. A series of stable inorganic electrides with a large nonlinear optical response and deep-ultraviolet transparency were theoretically designed and investigated.