Department of Materials Engineering, Indian Institute of Science, Bengaluru 560012, India.
J Chem Theory Comput. 2023 Jul 11;19(13):4202-4215. doi: 10.1021/acs.jctc.3c00030. Epub 2023 Jun 17.
We assess the accuracy and computational efficiency of the recently developed meta-generalized gradient approximation (metaGGA) functional, restored regularized strongly constrained and appropriately normed (rSCAN), in transition metal oxide (TMO) systems and compare its performance against SCAN. Specifically, we benchmark the rSCAN-calculated oxidation enthalpies, lattice parameters, on-site magnetic moments, and band gaps of binary 3 TMOs against the SCAN-calculated and experimental values. Additionally, we evaluate the optimal Hubbard correction required for each transition metal (TM) to improve the accuracy of the rSCAN functional, based on experimental oxidation enthalpies, and verify the transferability of the values by comparing against experimental properties on other TM-containing oxides. Notably, including the -correction with rSCAN increases the lattice parameters, on-site magnetic moments, and band gaps of TMOs, apart from an improved description of the ground state electronic state in narrow band gap TMOs. The rSCAN and rSCAN+ calculated oxidation enthalpies follow the qualitative trends of SCAN and SCAN+, with rSCAN and rSCAN+ predicting marginally larger lattice parameters, smaller magnetic moments, and lower band gaps compared to SCAN and SCAN+, respectively. We observe the overall computational time (i.e., for all ionic+electronic steps) required for rSCAN(+) to be lower than SCAN(+). Thus, the rSCAN(+) framework can offer a reasonably accurate description of the ground state properties of TMOs with better computational efficiency than SCAN(+).
我们评估了最近开发的元广义梯度近似（metaGGA）函数，即恢复正则化强约束和适当归一化（rSCAN），在过渡金属氧化物（TMO）系统中的准确性和计算效率，并将其性能与 SCAN 进行了比较。具体来说，我们基准测试了 rSCAN 计算的二元 3TMO 的氧化焓、晶格参数、局域磁矩和能带隙，与 SCAN 计算和实验值进行了比较。此外，我们根据实验氧化焓评估了每个过渡金属（TM）所需的最优 Hubbard 校正，以提高 rSCAN 函数的准确性，并通过与其他含 TM 氧化物的实验性质进行比较来验证 值的可转移性。值得注意的是，在 rSCAN 中包含 -校正会增加 TMO 的晶格参数、局域磁矩和能带隙，除了对窄带隙 TMO 的基态电子态的描述有所改善。rSCAN 和 rSCAN+计算的氧化焓遵循 SCAN 和 SCAN+的定性趋势，与 SCAN 和 SCAN+相比，rSCAN 和 rSCAN+分别预测出略大的晶格参数、略小的磁矩和略低的能带隙。我们观察到 rSCAN(+)所需的总计算时间（即所有离子+电子步骤）低于 SCAN(+)。因此，rSCAN(+)框架可以提供 TMO 基态性质的合理准确描述，其计算效率优于 SCAN(+)。
