We predicted several N-rich structures under high pressure. C2/c-SrN4 can make the ambient-pressure recovery possible. The energy densities for C2/m-SrN3 and P1̄-SrN5 are 1.08 and 1.09 kJ g−1, respectively, similar to that of common energy materials.

The structural phase transition, electronic properties, and bonding properties of antimony nitrides have been studied by using a first principles method.

Two new monoclinic P1̄-CaN3 and C2/m-CaN3 are predicted to become energetically stable under low pressure. For the first time, we identify one novel phase featuring charged “N6” chain in the P1̄-CaN3 structure.