Recoverable Zigzag N₄ Chains in High‐Pressure Synthesized Cerium Polynitride

Abstract Metal polynitrides have raised significant interest for their applications as potential high‐energy‐density materials (HEDMs). Despite extensive research on energetic polynitrogen species, reducing synthesis pressures and realizing their recovery at ambient conditions remain challenging. Here, for the first time, the zigzag N₄ chains are successfully stabilized in the new polynitride Ce₂N₆ and recovered to ambient pressure and temperature by introducing cerium nitride as a precursor. The stable mechanism of the recoverable N₄ chain originates from the large quantity of charge captured, the favorable bonding environment, and low structural enthalpy. This study reveals the crucial role of precursors in stabilizing and recovering polynitrogen species, providing an alternative route to design and prepare novel HEDMs.