FAPbI3_tetragonal&cubic

Initial structure of FAPbI3 of cubic phase was obtained through CIF file reported in previous report. While for tetragonal phase, no such CIF file could be found. Thus, we directly substitute Cs+ for FA+ in tetragonal phase CsPbI3, and then the resulting structure was relaxed through DFT calculation for the most stable structure. According to the usually inaccurate position of light element, we only apply structure relaxation calculation on FA+ while the Pb2+ and I- remain still.Structure relaxation and band-structure calculations are performed with plane-wave pseudopotential approach implemented in DS-PAW package. The exchange-correlation effects are concerned by PBE functional. The plane-wave cutoff energy was set to be 300.0 eV. The k-point number we set to be 5 × 5 × 5 for cubic phase and 4 × 4 × 5 for tetragonal phase respectively. Due to the heavy atom contained in perovskite materials, spin orbit coupling is included in DFT calculation for describing the real physical scenario.立方相FAPbI₃的初始结构通过既往研究报道的晶体学信息文件（Crystallographic Information File）获取。针对四方相，未检索到可用的此类文件，故我们直接在四方相CsPbI₃中将FA⁺替换为Cs⁺，随后通过密度泛函理论（Density Functional Theory）计算对所得结构进行弛豫以得到最稳定构型。考虑到轻元素的原子位置通常难以精准确定，我们仅对FA⁺实施结构弛豫计算，而Pb²⁺与I⁻保持固定。结构弛豫与能带结构计算采用DS-PAW软件包所集成的平面波赝势方法完成。交换关联效应通过PBE泛函进行描述。平面波截断能设置为300.0 eV。针对立方相与四方相，我们分别设置5×5×5与4×4×5的k点网格。鉴于钙钛矿材料含有重原子，我们在DFT计算中引入自旋轨道耦合（Spin-orbit coupling）以更真实地还原物理场景。

搜集汇总

背景与挑战

背景概述

该数据集提供了FAPbI3立方相和四方相的初始结构及其DFT计算结果，包括能带结构和态密度，适用于材料科学和物理学研究。