最优化“调控”区间分离密度泛函理论的研究进展

Recent Advances in the Optimally“Tuned”Range-Separated Density Functional Theory

发展精确、高效的交换-关联泛函一直是密度泛函理论工作者所追求的神圣目标。传统密度泛函被证实在计算原子或分子体系的某些基态和激发态性能时存在困难,而且预测不具有普适性;另一方面,一些高水平方法如耦合簇(CC)理论和基于格林函数(G)和屏蔽库仑作用(W)近似的多体微扰理论(MBPT),尽管相对精确但往往需要消耗昂贵的计算成本,因而其研究体系的尺寸和实用性受到了很大的限制。近年来,"最优化"调控区间分离泛函的发展在一定程度上使得上述问题得到改善,尤其是在消耗较少的计算成本前提下能够达到与高水平方法相媲美的预测精度,引起了越来越多的关注。本文首先简要回顾了密度泛函领域的理论背景,在区间分离密度泛函理论的基础上,重点介绍了最优化"调控"的概念;并且结合近期的理论工作对其在实际计算时的表现进行评价;最后,就最优化"调控"方法的前景和应用进行了展望。

It is the goal of density functional theory （DFT） researchers to develop the functional formalism of exchange-correlation （XC） with high accuracy and efficiency. Conventional functionals have issues when predicting the properties of the ground and excited states of atomic and molecular systems, and they do not show universal predictions. On the other hand, high-level theory methods such as the couple-cluster （CC） method and many-body perturbation theory （MBPT） based on GW （i.e., the dressed Green＇s function （G） and the dynamically screened Coulomb interaction （W）） approximation require very expensive computational cost and therefore the size of the systems studied and the practicability are limited. Recently, the optimally tuned range-separated （RS） functional has been developed to partly alleviate the above issues and has attracted great attention because it can achieve a level of accuracy comparable to the high-level method but with low computational cost. In this review, we first provide an overview of the theory in this field and then introduce the optimal tuning concept based on the RS functional. We combine the recent theoretical studies to evaluate their performance in practical calculations. Finally, we give some prospects for the future development and application of the optimally tuned approach.