An ab initio study using density functional theory (DFT) is carried out to explore the structural, electronic, and optical properties of vanadium gallate (VGaO₃) and niobium gallate (NbGaO₃). The structural properties of these compounds are determined by using the full-potential linearized augmented plane wave (FP-LAPW) technique as implemented in WIEN2k with a standard functional, i.e., the Perdew–Burke–Ernzerhof generalized gradient approximation (PBE-GGA). In addition, the local density approximation plus Hubbard parameter (LDA + U) is employed to calculate the electronic bandgap and total and partial density of states (TDOS and PDOS), to overcome the limitation of the PBE-GGA functional in terms of underestimation of the electronic bandgap. The values computed for the indirect bandgap of VGaO₃ and NbGaO₃ are 0.45 and 0.51 eV, respectively, indicating that both materials are semiconductors in nature. The PDOS of the studied materials reveal that 3d-states of vanadium atoms, 4d-states of niobium atoms, and 2p-states of oxygen atoms form the valence band. Moreover, the Kramer–Kronig relations are used to compute the optical properties of the title compounds. The dielectric functions, refractive index, optical conductivity, absorption coefficient, extinction coefficient, energy loss function, and reflectivity of these materials are also computed. The results for the studied properties reveal that NbGaO₃ exhibits better properties than VGaO₃ for use in optoelectronic applications.

一个从头研究使用密度泛函理论（DFT）进行探索钒没食子酸酯的结构，电子和光学性质（VGaO ₃和铌没食子酸酯）（NbGaO ₃）。这些化合物的结构特性是通过使用WIEN2k中采用的标准功能（即Perdew-Burke-Ernzerhof广义梯度逼近（PBE-GGA））使用全势线性化增强平面波（FP-LAPW）技术确定的。另外，采用局部密度近似加Hubbard参数（LDA + U）来计算电子带隙以及状态的总和部分密度（TDOS和PDOS），以克服PBE-GGA功能在低估下的局限性。电子带隙。为VGaO ₃和NbGaO ₃的间接带隙计算的值分别为0.45和0.51 eV，表明这两种材料本质上都是半导体。研究材料的PDOS显示3 d钒原子的-态，铌原子的4 d-态和氧原子的2 p-态形成价带。此外，使用Kramer-Kronig关系式来计算标题化合物的光学性质。还计算了这些材料的介电函数，折射率，光导率，吸收系数，消光系数，能量损失函数和反射率。研究性质的结果表明，NbGaO ₃具有比VGaO ₃更好的性质，可用于光电应用。