The current research work theoretically presents various pressure-induced physical properties of potassium niobate with a cubic structure of 2 × 2 × 2 optimized supercell. The employed exchange-correlation function is GGA with the PBE approach in the DFT-based CASTEP simulation tool. The noted bandgap exhibits a rising trend from 1.518 eV to 2.013 eV with an indirect semiconductor nature and this energy bandgap nature remains the same throughout under the external isotropic static pressure effect. The pressure-induced total and partial density of states were studied to confirm the degree of localized electrons in various bands. Moreover, according to Born stability criteria potassium niobate is found mechanically stable and possesses an anisotropic nature. It exhibits brittle nature at 0.00 GPa and 10 GPa whereas it is found ductile from 20 GPa to 100 GPa. It exhibits a super-hard nature from 0.0 to 30 GPa and an ultra-hard nature from 40 to 100 GPa. The Debye temperature and melting temperature increase as pressure rises. Furthermore, several optical features were examined under the effect of pressure, and it was observed that the optical curves slightly shifted toward higher energies with increasing pressure. The overall analysis exhibits that KNbO is a promising material for long-term photocatalytic activity.

中文翻译：

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使用光催化应用第一性原理计算 KNbO3 的压力诱导物理性质

目前的研究工作从理论上呈现了具有2×2×2优化超晶胞立方结构的铌酸钾的各种压力引起的物理性质。采用的交换相关函数是基于 DFT 的 CASTEP 模拟工具中采用 PBE 方法的 GGA。所指出的带隙表现出从 1.518 eV 到 2.013 eV 的上升趋势，具有间接半导体性质，并且这种能带隙性质在外部各向同性静压效应下始终保持不变。研究了压力引起的总态密度和部分态密度，以确认不同能带中电子的局域化程度。此外，根据玻恩稳定性标准，铌酸钾具有机械稳定性并具有各向异性。它在 0.00 GPa 和 10 GPa 下表现出脆性，而在 20 GPa 到 100 GPa 下表现出延展性。它表现出0.0至30 GPa的超硬性质和40至100 GPa的超硬性质。德拜温度和熔化温度随着压力升高而升高。此外，在压力作用下检查了几个光学特征，并观察到随着压力的增加，光学曲线稍微向更高能量移动。总体分析表明，KNbO 是一种有前景的长期光催化活性材料。