Liu Renxi, Zheng Daye, Liang Xinyuan, Ren Xinguo, Chen Mohan, Li Wenfei
HEDPS, CAPT, College of Engineering, Peking University, Beijing 100871, People's Republic of China.
Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 90871, People's Republic of China.
J Chem Phys. 2023 Aug 21;159(7). doi: 10.1063/5.0160726.
Kohn-Sham density functional theory (DFT) is nowadays widely used for electronic structure theory simulations, and the accuracy and efficiency of DFT rely on approximations of the exchange-correlation functional. By including the kinetic energy density τ, the meta-generalized-gradient approximation (meta-GGA) family of functionals achieves better accuracy and flexibility while retaining the efficiency of semi-local functionals. For example, the strongly constrained and appropriately normed (SCAN) meta-GGA functional has been proven to yield accurate results for solid and molecular systems. We implement meta-GGA functionals with both numerical atomic orbitals and plane wave bases in the ABACUS package. Apart from the exchange-correlation potential, we also discuss the evaluation of force and stress. To validate our implementation, we perform finite-difference tests and convergence tests with the SCAN, rSCAN, and r2SCAN meta-GGA functionals. We further test water hexamers, weakly interacting molecules from the S22 dataset, as well as 13 semiconductors using the three functionals. The results show satisfactory agreement with previous calculations and available experimental values.
如今，科恩-沈密度泛函理论（DFT）被广泛用于电子结构理论模拟，DFT的准确性和效率依赖于交换相关泛函的近似。通过包含动能密度τ，元广义梯度近似（meta-GGA）泛函家族在保持半局部泛函效率的同时，实现了更好的准确性和灵活性。例如，强约束适当归一化（SCAN）元-GGA泛函已被证明对固体和分子系统能产生准确的结果。我们在ABACUS软件包中使用数值原子轨道和平面波基实现了元-GGA泛函。除了交换相关势，我们还讨论了力和应力的评估。为了验证我们的实现，我们使用SCAN、rSCAN和r2SCAN元-GGA泛函进行了有限差分测试和收敛测试。我们进一步使用这三种泛函测试了水六聚体、S22数据集中的弱相互作用分子以及13种半导体。结果与先前的计算和现有实验值显示出令人满意的一致性。
