Abstract The aim of this study is to calculate the structural, electronic and optical properties of M1-xPrxF2+x (M = Ba, Ca, x = 0.25). The calculations are performed by the spin-polarized density functional theory (DFT) combined with Hubbard U correction method. The band gaps of Ba0.75Pr0.25F2.25 and Ca0.75Pr0.25F2.25are calculated and compared to the binary fluorides BaF2 and CaF2. It is found that the band gaps of the strongly substituted compounds in Praseodymium are smaller than those of the binary materials. The values obtained are 3.21, 2.77, 6.95, 7.14 eV for Ba0.75Pr0.25F2.25, Ca0.75Pr0.25F2.25, BaF2 and CaF2 respectively. The comparison between Ba0.75Pr0.25F2.25 and Ca0.75Pr0.25F2.25 is discussed by computing the optical parameters using LSDA and LSDA + U approximations, such as dielectric function, refractive index, reflectivity, absorption, extinction coefficient and energy loss function over a wide range of energy, 0.0–40.0eV. These results would provide a theoretical reference for fundamental science as well as technological application of these compounds. The electronic and optical properties predicted in this work for M1-xPrxF2+x (M = Ba, Ca, x = 0.25) may serve as reference for the other experimental and theoretical studies.

中文翻译：

---

M1-xPrxF2+x (M= Ca, Ba, x=0.25) 的结构、电子和光学性质的 DFT+U 研究

摘要 本研究的目的是计算 M1-xPrxF2+x (M = Ba, Ca, x = 0.25) 的结构、电子和光学性质。计算是通过自旋极化密度泛函理论 (DFT) 结合哈伯德 U 校正方法进行的。计算 Ba0.75Pr0.25F2.25 和 Ca0.75Pr0.25F2.25 的带隙并与二元氟化物 BaF2 和 CaF2 进行比较。发现镨中强取代化合物的带隙小于二元材料的带隙。对于 Ba0.75Pr0.25F2.25、Ca0.75Pr0.25F2.25、BaF2 和 CaF2，获得的值分别为 3.21、2.77、6.95、7.14 eV。Ba0.75Pr0.25F2.25 和 Ca0.75Pr0.25F2.25 之间的比较是通过使用 LSDA 和 LSDA + U 近似计算光学参数来讨论的，例如介电函数、折射率、反射率、吸收、消光系数和能量损失函数在很宽的能量范围内，0.0-40.0eV。这些结果将为这些化合物的基础科学和技术应用提供理论参考。在这项工作中预测的 M1-xPrxF2+x (M = Ba, Ca, x = 0.25) 的电子和光学性质可以作为其他实验和理论研究的参考。