Lattice dynamic properties of the tetragonal modification of ZnP2 and CdP2 crystals (space group P41212, no. 92) are calculated within the density functional theory. Theoretical results are shown to compare favorably with available Raman scattering and infrared reflection/transmission experimental data, which allows assignment of Raman-and infrared-active modes to the specific lattice eigenmodes. It is confirmed that several distinct features of vibrational spectra of these compounds steam from the presence of four phosphorous spiraling chains within crystallographic unit cell.

中文翻译：

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四方ZnP2和CdP2晶体中的拉曼和红外声子：密度泛函研究

在密度泛函理论中计算了 ZnP2 和 CdP2 晶体（空间群 P41212，编号 92）的四方改性的晶格动力学特性。理论结果显示与可用的拉曼散射和红外反射/透射实验数据相比更有利，这允许将拉曼和红外活动模式分配给特定的晶格本征模式。已经证实，这些化合物的振动光谱的几个不同特征是由于晶体晶胞内存在四个磷螺旋链而产生的。