Zhang Linyao, Shu Yinan, Xing Chang, Chen Xiye, Sun Shaozeng, Huang Yudong, Truhlar Donald G
School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, PR China.
School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, PR China.
J Chem Theory Comput. 2022 Jun 14;18(6):3523-3537. doi: 10.1021/acs.jctc.2c00242. Epub 2022 May 17.
The many-body approximation, especially the method, has been widely used for condensed matter and molecules to calculate quasiparticle energies for ionization, electron attachment, and band gaps. Because calculations are well-known to have a strong dependence on the orbitals, the goal of the present work is to provide guidance on the choice of density functional used to generate orbitals and to recommend a choice that gives the most broadly accurate results. We have systematically investigated the dependence of calculations on the orbitals for 100 molecules and 8 crystals by considering orbitals obtained with a diverse set of Kohn-Sham (KS) and generalized KS (GKS) functionals (63 functionals plus Hartree-Fock). The percentage of Hartree-Fock exchange employed in density functionals has been found to have strong influence on the predicted molecular ionization energy and crystal fundamental band gaps (with optimum values between 40 and 56%), but to have less effect on predicting molecular electron affinities. The low cost of the Gaussian implementation, even with hybrid functionals in periodic calculations, the better performance of global hybrids as compared to range-separated hybrids of either than screened exchange or long-range-corrected type, and the relatively low cost of global-hybrid-functional periodic calculations using Gaussians means that one can employ global-hybrid functionals at a very reasonable cost and obtain more accurate band gaps of semiconductors than are obtained by the methods currently widely employed, namely local gradient approximations. We single out three global-hybrid functionals that give especially good results for both molecules (100 in the test set) and crystals (8 in the test set, for all of which our benchmark data are the proper band gap rather than an optical band gap uncorrected for exciton effects).
多体近似，尤其是该方法，已广泛应用于凝聚态物质和分子，以计算电离、电子附着和带隙的准粒子能量。由于众所周知，计算对轨道有很强的依赖性，因此本工作的目标是为用于生成轨道的密度泛函的选择提供指导，并推荐一种能给出最广泛准确结果的选择。我们通过考虑用各种Kohn-Sham（KS）和广义KS（GKS）泛函（63种泛函加Hartree-Fock）获得的轨道，系统地研究了100个分子和8种晶体的计算对轨道的依赖性。已发现密度泛函中使用的Hartree-Fock交换百分比对预测的分子电离能和晶体基本带隙有很大影响（最佳值在40%至56%之间），但对预测分子电子亲和势的影响较小。高斯实现的低成本，即使在周期性计算中使用混合泛函时也是如此，与筛选交换或长程校正类型的范围分离混合泛函相比，全局混合泛函的性能更好，以及使用高斯的全局混合泛函周期性计算成本相对较低，这意味着人们可以以非常合理的成本使用全局混合泛函，并获得比目前广泛使用的方法（即局部梯度近似）更准确的半导体带隙。我们挑选出三种全局混合泛函，它们对分子（测试集中的100个）和晶体（测试集中的8个，对于所有这些晶体，我们的基准数据是适当的带隙而不是未校正激子效应的光学带隙）都给出特别好的结果。
