In their recent communication [Phys. Rev. Lett., 117, 073001 (2016)] Tao and Mo presented a semi-local density functional derived from the density matrix expansion of the exchange hole localised by a general coordinate transformation. We show that the order-of-limits problem present in the functional, dismissed as harmless in the original publication, causes severe errors in predicted phase transition pressures. We also show that the claim that lattice volume prediction accuracy exceeds that of existing similar functionals was based on comparison to reference data that misses anharmonic zero-point expansion and consequently overestimates accuracy. By highlighting these omissions, we give a more accurate assessment of the Tao-Mo functional and show a simple route to resolving the problems.
It is highlighted recently that the Tao-Mo (TM) [Phys. Rev. Lett. 117, 073001 (2016)] semilocal exchange-correlation energy functional suffers from the order-of-limit problem, which affects the functional performance for phase transition pressures [J. Chem. Phys. 152, 244112 (2020)]. The root of the order-of-limit problem of the TM functional inherent within the interpolation function, which switches between the compact density and the slowly varying density. In this paper, we propose a different switch function that avoids the order-of-limit problem and interpolates correctly between the comp…
Role of exact exchange in thermally-assisted-occupation density functional theory: A proposal of new hybrid schemes
我们提出了将精确交换结合到热辅助占据密度泛函理论（TAO-DFT）中的混合方案[J. - D. Chai，J.Chem.Phys.136，154104（2012）]，以改进对非局部交换效应的描述。通过一些简单的修改，Kohn-Sham密度泛函理论（KS-DFT）中的整体和距离分离的杂化泛函可以与TAO-DFT无缝结合。与KS-DFT中的全局混合泛函相比，TAO-DFT中所得的全局混合泛函对于具有强静态相关效应的系统（例如，H2和N2的解离、扭曲乙烯和线性并苯的电子性质），同时对于没有强静态相关效应的系统保持类似的性能。此外，通过在混合TAO-DFT中引入色散校正，可以有效地实现对非共价相互作用的合理准确描述。相对于TAO-DFT中的半局域密度泛函，TAO-DFT中的全局杂化泛函在热化学、动力学、反应能和优化几何结构等广泛的应用中表现出优越的性能.
Thermally-assisted-occupation density functional theory with generalized-gradient approximations
我们扩展了最近提出的热辅助占据密度泛函理论（TAO-DFT）[J. - D. Chai，J.Chem.Phys.136，154104（2012）]到广义梯度近似（GGA）交换相关密度泛函。相对于我们之前的TAO-LDA（即，TAO-DFT的局域密度近似），所得TAO-GGA对于广泛的应用，例如热化学、动力学和反应能是显著优越的。对于非共价相互作用，TAO-GGA与经验色散校正显示出优异的性能。由于TAO-LDA和TAO-GGA对具有强静态相关效应的系统的计算效率，它们被应用于研究电子性质（例如，单重态-三重态能隙、垂直电离势、垂直电子亲合势、基本能隙和对称化的冯诺伊曼熵），这对于传统的电子结构方法是非常具有挑战性的。并苯的基态在所有的链长下都是单态。随着并苯长度的增加，单重态-三重态能隙、垂直电离势和基本能隙单调减小，而垂直电子亲合势和对称化冯诺伊曼熵（即，多根特征的度量）单调地增加。
Finite-temperature adiabatic-connection reduced density-matrix functional theory: a unified framework for i-DMFT and TAO-DFT
Institute of Physics, Chinese Academy of Sciences（中国科学院物理研究所）；School of Physical Sciences, University of Chinese Academy of Sciences（中国科学院大学物理科学学院）；Department of Applied Physics, Nanjing University of Science and Technology（南京理工大学应用物理系）
Finite-Temperature Thermally-Assisted-Occupation Density Functional Theory, Ab Initio Molecular Dynamics, and Quantum Mechanics/Molecular Mechanics Methods
National Taiwan University（台湾大学）；Department of Physics, National Taiwan University（台湾大学物理系）；Center for Theoretical Physics and Center for Quantum Science and Engineering, National Taiwan University（台湾大学理论物理中心与量子科学与工程中心）；Physics Division, National Center for Theoretical Sciences（国家理论科学中心物理组）
The time-dependent density functional theory (TDDFT) has been broadly used to investigate the excited-state properties of various molecular systems. However, the current TDDFT heavily relies on outcomes from the corresponding ground-state density functional theory (DFT) calculations which may be prone to errors due to the lack of proper treatment in the non-dynamical correlation effects. Recently, thermally-assisted-occupation density functional theory (TAO-DFT) [J.-D. Chai, \textit{J. Chem. Phys.} \textbf{136}, 154104 (2012)], a DFT with fractional orbital occupations, was proposed, explicitl…
Due to several attractive features, the meta-generalized-gradient approximations (meta-GGAs) are considered to be the most advanced and potentially accurate semilocal exchange-correlation functionals in the rungs of the Jacob's ladder of Density Functional Theory. So far, several meta-GGA are proposed by fitting to the test sets or/and satisfying as many as known exact constraints. Although the density overlap is treated by modern meta-GGA functionals efficiently, for non-covalent interactions, a long-range dispersion correction is essential. In this work, we assess the benchmark performance o…
Adding Temperature to the Adiabatic Connection: Hybrid Functionals for Static and Dynamic Correlation
Arnold Sommerfeld Centre for Theoretical Physics, Ludwig-Maximilians-Universität München（路德维希-马克西米利安慕尼黑大学阿诺德·索末菲理论物理中心）；Department of Computer Science, Oslo Metropolitan University（奥斯陆都市大学计算机系）；Department of Physical Chemistry, University of Geneva（日内瓦大学物理化学系）
The many-body problem can in general not be solved exactly, and one of the most prominent approximations is to build perturbation expansions. A huge variety of expansions is possible, which differ by the quantity to be expanded, the expansion variable, the starting point, and ideas how to resum or terminate the series. Although much has been discussed and much has been done, some choices were made for historical reasons, in particular, limited computation or storage capacities. The present work aims at examining the justifications for different choices made in different contexts, by comparing …
