High-pressure nitrogen chemistry has expanded at a formidable rate over the past decade, unveiling the chemical richness of nitrogen. Here, the Zn-N system is investigated in laser-heated diamond anvil cells by synchrotron powder and single-crystal X-ray diffraction, revealing three hitherto unobserved nitrogen compounds: β-Zn₃N₂, α-ZnN₄, and β-ZnN₄, formed at 35.0, 63.5, and 81.7 GPa, respectively. Whereas β-Zn₃N₂ contains the N^3– nitride, both ZnN₄ solids are found to be composed of polyacetylene-like [N₄]_∞^2– chains. Upon the decompression of β-ZnN₄ below 72.7 GPa, a first-order displacive phase transition is observed from β-ZnN₄ to α-ZnN₄. The α-ZnN₄ phase is detected down to 11.0 GPa, at lower pressures decomposing into the known α-Zn₃N₂ (space group Ia3̅) and N₂. The equations of states of β-ZnN₄ and α-ZnN₄ are also determined, and their bulk moduli are found to be K₀ = 126(9) GPa and K₀ = 76(12) GPa, respectively. Density functional theory calculations were also performed and provide further insight into the Zn-N system. Moreover, comparing the Mg-N and Zn-N systems underlines the importance of minute chemical differences between metal cations in the resulting synthesized phases.

中文翻译：

---

β-Zn3N2 氮化物和 α-ZnN4 和 β-ZnN4 多氮化合物的高压合成

在过去的十年中，高压氮化学以惊人的速度发展，揭示了氮的化学丰富性。在这里，Zn-N 系统通过同步加速器粉末和单晶 X 射线衍射在激光加热的金刚石砧座中进行研究，揭示了三种迄今为止未观察到的氮化合物：β-Zn ₃ N ₂、α-ZnN ₄和 β- ZnN _{4 分别}在35.0、63.5和81.7 GPa下形成。而β-Zn ₃ N ₂包含N ^3-氮化物，两种ZnN ₄固体都被发现由聚乙炔类[ N ₄ ] _∞ ^2-链组成。β-ZnN 减压时₄低于72.7 GPa，观察到从β-ZnN ₄到α-ZnN ₄的一级位移相变。检测到α-ZnN ₄相低至 11.0 GPa，在较低压力下分解为已知的 α-Zn ₃ N ₂（空间群Ia 3̅）和 N ₂。还确定了β-ZnN ₄和α-ZnN ₄的状态方程，发现它们的体积模量为K ₀ = 126(9) GPa 和K ₀= 76(12) GPa，分别。还进行了密度泛函理论计算，并提供了对 Zn-N 系统的进一步了解。此外，比较 Mg-N 和 Zn-N 系统强调了所得合成相中金属阳离子之间微小化学差异的重要性。