In this study, Matlockite (PbFCl) type SrFI compound with a two-dimensional layered structure has been studied using density functional theory (DFT) and generalized gradient approximation (GGA) under high hydrostatic pressure. Calculations were made using the Siesta Method. In ambient conditions, matlockite type structures crystallize in tetragonal structure with space group P₄/nmm. In nature, these structures are known as alkaline earth fluoro-halides. When gradually increasing pressures were applied to this structure, the phase transition was observed to the orthorhombic structure with space group Pmmn. In addition to these studies, some physical properties of SrFI, such as lattice parameters, bulk modulus, the derivative of the bulk modulus, and volume values were also calculated. On the other hand, total energy and enthalpy calculations were made to obtain the phase transition pressure values that are in good agreement with the experimental results. According to these calculations, phase transition pressure was predicted at about 44.8 GPa. Besides, how electronic and elastic properties of SrFI compound change with applied pressure were also examined. In the electronic structure calculations, about 5.09 eV band gap value was obtained for P4/nmm phase at 0 GPa pressure. Under increasing pressure, the 0.16 eV band gap value was calculated for the Pmmn phase of SrFI. According to these results, the stable phases obtained of the SrFI compound have semiconductor characters since the both phases have a conceivable band gap. In addition, elastic constants were calculated and two structures of SrFI were found to be mechanically stable.

在这项研究中，使用密度泛函理论 (DFT) 和广义梯度近似 (GGA) 在高静水压力下研究了具有二维层状结构的 Matlockite (PbFCl) 型 SrFI 化合物。使用 Siesta 方法进行计算。在环境条件下，硅藻土型结构以空间群 P _{4 的}四方结构结晶/毫米。在自然界中，这些结构被称为碱土金属氟卤化物。当对该结构施加逐渐增加的压力时，观察到相变到空间群为 Pmmn 的正交结构。除了这些研究之外，还计算了 SrFI 的一些物理特性，例如晶格参数、体积模量、体积模量的导数和体积值。另一方面，进行总能量和焓计算以获得与实验结果非常一致的相变压力值。根据这些计算，预测相变压力约为 44.8 GPa。此外，还研究了 SrFI 化合物的电子和弹性特性如何随施加的压力而变化。在电子结构计算中，大约为 5。在 0 GPa 压力下获得 P4/nmm 相的 09 eV 带隙值。在增加的压力下，SrFI 的 Pmmn 相的带隙值为 0.16 eV。根据这些结果，由 SrFI 化合物获得的稳定相具有半导体特性，因为这两个相都具有可想象的带隙。此外，计算了弹性常数，发现 SrFI 的两种结构在机械上是稳定的。