The electronic and atomic structure of a bulk 2D layered van-der-Waals compound CdPS3 was studied in the low (R3) and room (C2/m) temperature phases using first-principles calculations within the periodic linear combination of atomic orbitals method with hybrid meta exchange-correlation M06 functional. The calculation results reproduce well the experimental crystallographic parameters. The value of the indirect band gap Eg=3.4 eV for the room-temperature monoclinic C2/m phase is close to the experimental one, while the indirect band gap Eg=3.3 eV was predicted for the low-temperature trigonal R3 phase. The effect of hydrostatic pressure on the band gap in both phases was studied in the pressure range from 0 to 40 GPa. In both cases, the pressure dependence of the band gap passes through a maximum, but at different pressures. In the R3 phase, the band gap reaches its maximum value of ~4 eV at ~30 GPa, whereas in the C2/m phase, the maximum value of ~3.6 eV is reached already at ~8 GPa.

中文翻译：

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CdPS3 低温和室温相的第一性原理 LCAO 研究

在低 (R3) 和室温 (C2/m) 温度相中，使用原子轨道方法与杂化的周期性线性组合内的第一性原理计算，研究了块状 2D 层状范德华化合物 CdPS3 的电子和原子结构。元交换相关 M06 功能。计算结果很好地再现了实验晶体学参数。室温单斜 C2/m 相的间接带隙 Eg=3.4 eV 值与实验值接近，而预测低温三角 R3 相的间接带隙 Eg=3.3 eV。在 0 到 40 GPa 的压力范围内研究了静水压力对两相带隙的影响。在这两种情况下，带隙的压力依赖性通过最大值，但在不同的压力下。在 R3 阶段，