We report the results of pressure-induced semiconductor-metal phase transition of the semiconducting chalcogenide compound KPSe6 under high pressure using the ab initio methods. The ground-state energy calculations were performed within density functional theory and the generalized gradient approximation using the pseudopotential method with plane-wave basis sets. The projector augmented-wave (PAW) pseudopotentials were used in our calculation. The optimized lattice parameters were found from total energy calculations as 13 Bohr, 1.6 Bohr, and 1.8 Bohr for cell dimensions one, two, and three, respectively, which are in good agreement with experimental calculations. At zero pressure, the material portrayed a semiconducting property with a direct bandgap of ≈1.7 eV. As we subjected the material to pressure, the band gap was observed to reduce until it disappeared. The phase transition from the semiconductor to metal was found to occur at ∼45 GPa, implying that the material underwent metallization as pressure was increased further.

中文翻译：

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硫属化物化合物 KPSe6 的半导体-金属相变的 Ab Initio 高压研究

我们使用 ab initio 方法报告了高压下半导体硫属化物化合物 KPSe6 的压力诱导的半导体-金属相变的结果。基态能量计算是在密度泛函理论和广义梯度近似中使用具有平面波基组的赝势方法进行的。我们的计算中使用了投影增强波 (PAW) 赝势。从总能量计算中发现优化的晶格参数分别为 13 玻尔、1.6 玻尔和 1.8 玻尔，对于单元尺寸一、二和三，这与实验计算非常吻合。在零压力下，该材料表现出半导体特性，直接带隙约为 1.7 eV。当我们对材料施加压力时，观察到带隙减小直至消失。发现从半导体到金属的相变发生在~45 GPa，这意味着随着压力的进一步增加，材料经历了金属化。