论文标题
使用扫描（+U）的分层NAMNO2的稳定性和电子性能
Stability and electronic properties of layered NaMnO2 using the SCAN(+U)
论文作者
论文摘要
适当地考虑电子相关性对于预测分层过渡金属氧化物的性质很重要，这些金属氧化物吸引了大量注意作为钠离子电池的阴极材料。在这里，我们使用最近开发的强烈限制和适当的规范（SCAN）功能探索分层NAMNO2的声子和电子性能。我们还介绍了库仑相互作用U，以找到对MN 3D轨道的准确描述。声子分散曲线显示了扫描的结构稳定性，这与高NA浓度下的先前实验稳定性一致。另一方面，通过应用U观察到虚构的声子频率，这表明结构不稳定性。也就是说，扫描正确描述了分层namno2的声子特性，而扫描+u则没有。我们进一步探讨了Jahn-Teller（J-T）的稳定性和J-T失真的幅度，具体取决于U，发现扫描结果与Perdew-Burke-Ernzerhof功能性，PBE+U结果一致。我们的结果表明，扫描本身正确地描述了NAMNO2的物理特性，而无需明确添加U。
Considering electron correlation appropriately is important to predict the properties of layered transition metal oxides, which have drawn a lot of attention as cathode materials for sodium-ion batteries. Here, we explore the phonon and electronic properties of layered NaMnO2 using the recently developed strongly constrained and appropriately normed (SCAN) functional. We also introduce the Coulomb interaction U to find an accurate description of Mn 3d orbitals. The phonon dispersion curves show the structural stability with the SCAN, which is consistent with prior experimental stability at high Na concentrations. On the other hand, imaginary phonon frequencies were observed by applying U, which indicates structural instability. Namely, SCAN properly describes the phonon properties of layered NaMnO2 whereas SCAN+U does not. We further explore the Jahn-Teller (J-T) stability and magnitude of J-T distortion depending on U and find that SCAN results are consistent with Perdew-Burke-Ernzerhof functional, PBE+U results. Our results suggest that SCAN itself properly describes the physical properties of NaMnO2 without adding U explicitly.
