Nonlinear optical materials have attracted worldwide attention owing to their wide range of applications, specially in the laser field. Phosphates with noncentrosymmetric structures are potential candidates for novel ultraviolet (UV)-NLO materials, because they usually display short UV cut-off edges. In this work, a polyphosphate, the LiZnP₃O₉ polyphosphate crystals were grown through spontaneous crystallization from high-temperature melts. It crystallizes in the orthorhombic space group P2₁2₁2₁ with unit cell parameters a = 8.330(3) Å, b = 8.520(3) Å, c = 8.635(3) Å, and Z = 4. In the structure, all the P atoms are coordinated by four oxygen atoms forming the [PO₄] tetrahedra and further connected to generate a zig-zag [PO₃]_∞ anionic framework. Thermal analysis, IR spectroscopy, UV–vis–NIR diffuse reflectance spectrum and powder second harmonic generation measurements are performed. In addition, the first-principles calculation was employed for better understanding the structure–property relationships of LiZnP₃O₉.

非线性光学材料由于其广泛的应用而引起了全世界的关注，特别是在激光领域。具有非中心对称结构的磷酸盐可能是新型紫外线（NUV）-NLO材料的潜在候选物，因为它们通常显示出短的紫外线截止边缘。在这项工作中，一种多磷酸盐，即LiZnP₃O₉多磷酸盐晶体是通过从高温熔体中自发结晶而生长的。它在正交晶空间群P2₁2₁2_1中结晶，晶胞参数为a= 8.330（3）Å，b= 8.520（3）Å，c= 8.635（3）Å，以及Z  =4。在该结构中，所有P原子均与形成[PO ₄ ]四面体的四个氧原子配位，并进一步连接以生成Z字形[PO ₃ ] _∞阴离子骨架。进行了热分析，红外光谱，紫外可见近红外漫反射光谱和粉末二次谐波的产生测量。此外，采用第一性原理计算可更好地理解LiZnP ₃ O ₉的结构-性质关系。