论文标题
固体和液体金属的laplacian级元化梯度近似
Laplacian-level meta-generalized gradient approximation for solid and liquid metals
论文作者
论文摘要
我们得出并激励拉普拉斯水平，无轨道的元元化梯度近似（LL-MGGA），用于交换相关能源，以$ sp $ sp $和$ sd $ sd $金属凝结物的准确地面属性为目标，而该密度仅适用于较弱的范围，而密度仅适用于较弱的范围。我们的无轨道动能密度的模型恢复了交换至R $^2 $扫描meta-GGA的四阶梯度扩展[Furness等，J。Phys。化学Lett。 11，8208（2020）]，产生了我们称之为ofr2的ll-mgga。 OFR2与扫描预测公共晶格常数的准确性相匹配，并提高了通过扫描和r $ $ $^2 $扫描而降级相对于PBE GGA值降级的碱金属，过渡金属和金属间的平衡性能。我们将Ofr2与R $^2 $ scan-l ll-mgga [D. Mejia-Rodriguez和S.B. Trickey，物理。 Rev. B 102，121109（2020）]并表明，对于固体的平衡性能，OFR2倾向于优于r $^2 $ scan-l，但是r $^2 $ scan-l比ofr2更好地描述了分子的雾化能量。为了获得分子和非金属凝结物的最佳准确性，我们继续建议扫描和r $^2 $扫描。详细讨论了数字性能，我们的工作为机器学习提供了前景。
We derive and motivate a Laplacian-level, orbital-free meta-generalized-gradient approximation (LL-MGGA) for the exchange-correlation energy, targeting accurate ground-state properties of $sp$ and $sd$ metallic condensed matter, in which the density functional for the exchange-correlation energy is only weakly nonlocal due to perfect long-range screening. Our model for the orbital-free kinetic energy density restores the fourth-order gradient expansion for exchange to the r$^2$SCAN meta-GGA [Furness et al., J. Phys. Chem. Lett. 11, 8208 (2020)], yielding a LL-MGGA we call OFR2. OFR2 matches the accuracy of SCAN for prediction of common lattice constants and improves the equilibrium properties of alkali metals, transition metals, and intermetallics that were degraded relative to the PBE GGA values by both SCAN and r$^2$SCAN. We compare OFR2 to the r$^2$SCAN-L LL-MGGA [D. Mejia-Rodriguez and S.B. Trickey, Phys. Rev. B 102, 121109 (2020)] and show that OFR2 tends to outperform r$^2$SCAN-L for the equilibrium properties of solids, but r$^2$SCAN-L much better describes the atomization energies of molecules than OFR2 does. For best accuracy in molecules and non-metallic condensed matter, we continue to recommend SCAN and r$^2$SCAN. Numerical performance is discussed in detail, and our work provides an outlook to machine learning.
