Three Mg₃(PO₄)₂ polymorphs (Mg₃(PO₄)₂-I, II, III) were synthesized at high-pressure and high-temperature conditions. The structures and vibrational properties of Mg₃(PO₄)₂ polymorphs were studied by X-ray diffraction (XRD), Raman spectroscopy, and density functional theory (DFT) calculations. The obvious different PO stretching vibrational modes were experimentally observed for Mg₃(PO₄)₂-I, II, III. The calculated vibrational frequencies were in good agreement with measurements. All the observed vibrational modes for Mg₃(PO₄)₂-I, II, III were well assigned based on the calculations, which provided a support for investigating and comparing vibrational properties of three Mg₃(PO₄)₂ polymorphs.

在高压和高温条件下合成了三个Mg ₃（PO ₄）₂多晶型物（Mg ₃（PO ₄）₂ -I，II，III）。通过X射线衍射（XRD），拉曼光谱和密度泛函理论（DFT）计算研究了Mg ₃（PO ₄）₂多晶型物的结构和振动性能。实验观察到Mg ₃（PO ₄）_2有明显的不同的P O拉伸振动模式。-I，II，III。计算出的振动频率与测量值非常吻合。根据计算结果，对观察到的Mg ₃（PO ₄）₂ -I，II，III的所有振动模式进行了很好的分配，这为研究和比较三种Mg ₃（PO ₄）₂多晶型的振动性质提供了支持。