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arXiv 2202.11531physics.chem-phcond-mat.other
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改进强相互作用极限处理的Kohn-Sham绝热连接模型的自洽实现

Self-Consistent Implementation of Kohn-Sham Adiabatic Connection Models with Improved Treatment of the Strong-Interaction Limit

S. Śmiga, F. Della Sala, P. Gori-Giorgi, E. Fabiano

摘要:

绝热连接模型(ACM)是建立精确交换关联泛函的有力工具,它介于弱相互作用和强相互作用之间。如果包含来自二阶微扰理论的精确弱相互作用展开,则这些泛函的自洽实现是具有挑战性的,并且在文献中仍然缺乏。在这项工作中,我们填补了这一空白,提出了一个完全自洽场(SCF)实现一些流行的ACM泛函。在弱相互作用下使用二阶微扰理论的同时,我们还引入了新的广义梯度近似(GGA),超出了通常的点电荷加连续模型,用于强相互作用下的前两个主导项,这对于确保鲁棒性和可靠性至关重要。然后,我们评估的SCF-ACM泛函的分子系统和原型强相关问题。我们发现,他们表现良好的总能量和电子密度和SCF轨道的影响是直接连接到ACM功能形式的准确性。对于H $_2$解离,SCF-ACM泛函相对于标准泛函产生显著的改进,这也要归功于对强耦合泛函使用新的GGA。

英文摘要:

Adiabatic connection models (ACMs), which interpolate between the limits of weak and strong interaction, are powerful tools to build accurate exchange-correlation functionals. If the exact weak-interaction expansion from second-order perturbation theory is included, a self-consistent implementation of these functionals is challenging and still absent in the literature. In this work we fill this gap by presenting a fully self-consistent-field (SCF) implementation of some popular ACM functionals. While using second-order perturbation theory at weak interactions, we have also introduced new generalised gradient approximations (GGA's), beyond the usual point-charge-plus-continuum model, for the first two leading terms at strong interactions, which are crucial to ensure robustness and reliability. We then assess the SCF-ACM functionals for molecular systems and for prototypical strong-correlation problems. We find that they perform well for both the total energy and the electronic density and that the impact of SCF orbitals is directly connected to the accuracy of the ACM functional form. For the H$_2$ dissociation the SCF-ACM functionals yield significant improvements with respect to standard functionals, also thanks to the use of the new GGA's for the strong-coupling functionals.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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