Mei Yuncai, Chen Zehua, Yang Weitao
Key Laboratory of Theoretical Chemistry of Environment, School of Chemistry and Environment, South China Normal University, Guangzhou 510006, China.
J Phys Chem Lett. 2020 Dec 3;11(23):10269-10277. doi: 10.1021/acs.jpclett.0c03133. Epub 2020 Nov 20.
The recently developed localized orbital scaling correction (LOSC) method shows the ability to systematically and size-consistently reduce the delocalization error existing in conventional density functional approximations (DFAs). However, the application of LOSC to DFAs was mainly through a post self-consistent field (SCF) manner, and few results from applying LOSC to DFAs in an SCF manner have been reported. The reason is that the originally proposed SCF approach to SCF-LOSC calculation uses an approximate Hamiltonian and encounters convergence problems easily in practice. In this work, we develop a new SCF approach with a correct Hamiltonian and achieve reliable SCF-LOSC calculations. We demonstrate the capability of the new SCF approach for SCF-LOSC to correctly describe the electron densities, total energies, and energy-level alignment for the molecular dissociation process, while conventional DFAs or LOSC-DFAs with post-SCF calculations show large errors. This work demonstrates that the new SCF approach for SCF-LOSC would be a promising method for studying problems for correct electron densities and energy-level alignments in large systems.
最近开发的定域轨道尺度校正(LOSC)方法显示出能够系统且大小一致地减少传统密度泛函近似(DFA)中存在的离域误差的能力。然而,LOSC在DFA中的应用主要是通过自洽场(SCF)后的方式,并且很少有关于以SCF方式将LOSC应用于DFA的结果被报道。原因是最初提出的用于SCF-LOSC计算的SCF方法使用了近似哈密顿量,在实际中容易遇到收敛问题。在这项工作中,我们开发了一种具有正确哈密顿量的新SCF方法,并实现了可靠的SCF-LOSC计算。我们证明了用于SCF-LOSC的新SCF方法能够正确描述分子解离过程中的电子密度、总能量和能级排列,而传统的DFA或进行SCF后计算的LOSC-DFA则显示出较大误差。这项工作表明,用于SCF-LOSC的新SCF方法将是研究大系统中正确电子密度和能级排列问题的一种有前途的方法。