Computational Chemistry Unit, RIKEN Advanced Institute for Computational Science, Kobe, Hyogo 6500047, Japan.
J Comput Chem. 2013 Apr 30;34(11):958-64. doi: 10.1002/jcc.23222. Epub 2013 Jan 8.
In this article, we show that the long-range-corrected (LC) density functionals LC-BOP and LCgau-BOP reproduce frontier orbital energies and highest-occupied molecular orbital (HOMO)-lowest-unoccupied molecular orbital (LUMO) gaps better than other density functionals. The negative of HOMO and LUMO energies are compared with the vertical ionization potentials (IPs) and electron affinities, respectively, using CCSD(T)/6-311++G(3df,3pd) for 113 molecules, and we found LC functionals to satisfy Koopmans' theorem. We also report that the frontier orbital energies and the HOMO-LUMO gaps of LC-BOP and LCgau-BOP are better than those of recently proposed ωM05-D (Lin et al., J. Chem. Phys. 2012, 136, 154109). We express the exact IP in terms of orbital relaxation, and correlation energies and hence calculate the relaxation and correlation energies for the same set of molecules. It is found that the LC functionals, in general, includes more relaxation effect than Hartree-Fock and more correlation effect than the other density functionals without LC scheme. Finally, we scan μ parameter in LC scheme from 0.1 to 0.6 bohr(-1) for the above test set molecules with LC-BOP functional and found our parameter value, 0.47 bohr(-1), is usefully applicable to our tested systems.
在本文中，我们表明，长程校正（LC）密度泛函 LC-BOP 和 LCgau-BOP 比其他密度泛函更好地再现了前沿轨道能量和最高占据分子轨道（HOMO）-最低未占据分子轨道（LUMO）能隙。使用 CCSD(T)/6-311++G(3df,3pd) 对 113 个分子进行计算，将 HOMO 和 LUMO 能量的负值分别与垂直电离势（IP）和电子亲和能进行了比较，我们发现 LC 泛函满足 Koopmans 定理。我们还报告说，LC-BOP 和 LCgau-BOP 的前沿轨道能量和 HOMO-LUMO 能隙优于最近提出的 ωM05-D（Lin 等人，J. Chem. Phys. 2012, 136, 154109）。我们将精确的 IP 表示为轨道弛豫和相关能量，因此为相同的分子集计算了弛豫和相关能量。结果表明，LC 泛函通常比 Hartree-Fock 包含更多的弛豫效应，比没有 LC 方案的其他密度泛函包含更多的相关效应。最后，我们使用 LC-BOP 函数对上述测试集分子从 0.1 到 0.6 bohr(-1) 扫描 LC 方案中的 μ 参数，并发现我们的参数值 0.47 bohr(-1) 对我们测试的系统非常有用。
