Pakdel Sahar, Olsen Thomas, Thygesen Kristian S
Computational Atomic-scale Materials Design (CAMD), Department of Physics, Technical University of Denmark, Kgs. Lyngby, Denmark.
NPJ Comput Mater. 2025;11(1):18. doi: 10.1038/s41524-024-01503-3. Epub 2025 Jan 24.
We conduct a systematic investigation of the role of Hubbard U corrections in electronic structure calculations of two-dimensional (2D) materials containing 3 transition metals. Specifically, we use density functional theory (DFT) with the PBE and PBE+U approximations to calculate the crystal structure, band gaps, and magnetic parameters of 638 monolayers. Based on a comprehensive comparison to experiments we first establish that the inclusion of the U correction worsens the accuracy for the lattice constants. Consequently, PBE structures are used for subsequent property evaluations. The band gaps show a significant dependence on U. In particular, for 134 (21%) of the materials the U parameter induces a metal-to-insulator transition. For the magnetic materials we calculate the magnetic moment, magnetic exchange coupling, and magnetic anisotropy parameters. In contrast to the band gaps, the size of the magnetic moments shows only weak dependence on U. Both the exchange energies and magnetic anisotropy parameters are systematically reduced by the U correction. On this basis we conclude that the Hubbard U correction will lead to lower predicted Curie temperatures in 2D materials. All the calculated properties are available in the Computational 2D Materials Database (C2DB).
我们对哈伯德U校正（Hubbard U corrections）在含3种过渡金属的二维（2D）材料电子结构计算中的作用进行了系统研究。具体而言，我们使用密度泛函理论（DFT），采用PBE和PBE+U近似来计算638种单层材料的晶体结构、带隙和磁参数。基于与实验的全面比较，我们首先确定包含U校正会降低晶格常数的计算精度。因此，后续的性质评估使用PBE结构。带隙对U有显著依赖性。特别是，对于134种（21%）材料，U参数会引发金属-绝缘体转变。对于磁性材料，我们计算了磁矩、磁交换耦合和磁各向异性参数。与带隙不同，磁矩大小对U的依赖性较弱。U校正会使交换能和磁各向异性参数都系统性降低。在此基础上，我们得出结论，哈伯德U校正会导致二维材料中预测的居里温度降低。所有计算得到的性质都可在计算二维材料数据库（C2DB）中获取。
