Npj Comput. Mater.: 材料计算精度控制的关键—跨不同程序和方法
作为理论和实验的重要补充，计算材料科学已经发展成为材料科学领域的一种新型研究范式。计算机运算能力的显著提升以及基于密度泛函理论（DFT）的第一性原理计算程序的逐步成熟，极大地推动了电子结构理论的广泛应用。这些程序本质上都是基于相同的物理原理，即使用有限基组展开并自洽求解Kohn-Sham方程。除了基组的选择不同之外，不同的程序在计算过程中采用的近似手段和数值方法也有所差异。这样就会带来不同程序所得结果之间的一致性问题。此外，计算参数的设置也会导致计算结果发生显著变化。因此，当使用的计算方法和参数不同，或当所考察的性质发生变化时，对这些不同来源的数据进行比较就存在着潜在的不确定性。
该文近期发表于npj Computational Materials 8：69 (2022)，英文标题与摘要如下，点击左下角“阅读原文”可以自由获取论文PDF。
Electronic-structure theory is a strong pillar of materials science. Many different computer codes that employ different approaches are used by the community to solve various scientific problems. Still, the precision of different packages has only been scrutinized thoroughly not long ago, focusing on a specific task, namely selecting a popular density functional, and using unusually high, extremely precise numerical settings for investigating 71 monoatomic crystals. Little is known, however, about method- and code-specific uncertainties that arise under numerical settings that are commonly used in practice. We shed light on this issue by investigating the deviations in total and relative energies as a function of computational parameters. Using typical settings for basis sets and k-grids, we compare results for 71 elemental and 63 binary solids obtained by three different electronic-structure codes that employ fundamentally different strategies. On the basis of the observed trends, we propose a simple, analytical model for the estimation of the errors associated with the basis-set incompleteness. We cross-validate this model using ternary systems obtained from the Novel Materials Discovery (NOMAD) Repository and discuss how our approach enables the comparison of the heterogeneous data present in computational materials databases.
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