Orthorhombic $\alpha {-\mathrm{MoO}}_3$ is a layered oxide with various applications and with excellent potential to be exfoliated as a 2D ultra-thin film or monolayer. In this paper, we present a first-principles computational study of its vibrational properties. Our focus is on the zone center modes, which can be measured by a combination of infrared and Raman spectroscopy. The polarization dependent spectra are simulated. Calculations are also performed for a monolayer form in which “double layers” of ${\mathrm{Mo}}_2{\mathrm{O}}_6$, which are weakly van der Waals bonded in the $\alpha$-structure, are isolated. Shifts in phonon frequencies are analyzed.

中文翻译：

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斜方晶α-MoO3和单层MoO3中计算的声子模式、红外和拉曼光谱

斜方晶系 $\alpha {-\mathrm{氧化钼}}_3$是一种具有多种应用的层状氧化物，具有被剥离为二维超薄膜或单层的极好潜力。在本文中，我们提出了其振动特性的第一性原理计算研究。我们的重点是区域中心模式，它可以通过红外和拉曼光谱的组合进行测量。模拟偏振相关光谱。还对单层形式进行计算，其中“双层”${\mathrm{莫}}_2{\mathrm{哦}}_6$，它们是弱范德瓦尔斯键合在 $\alpha$-结构，是孤立的。分析了声子频率的变化。