School of Chemistry, University of Nottingham, University Park, Nottingham, UK NG7 2RD.
Phys Chem Chem Phys. 2009 Nov 28;11(44):10350-8. doi: 10.1039/b912718f. Epub 2009 Sep 25.
We report calculations of core excitation energies and near-edge X-ray absorption fine structure (NEXAFS) spectra computed with time-dependent density functional theory (TDDFT). TDDFT with generalized gradient approximation and standard hybrid exchange-correlation functionals is known to underestimate core excitation energies. This failure is shown to be associated with the self-interaction error at short interelectronic distances. Short-range corrected hybrid functionals are shown to reduce the error in the computed core excitation energies for first and second row nuclei in a range of molecules to a level approaching that observed in more traditional excited states calculations in the ultraviolet region. NEXAFS spectra computed with the new functionals agree well with experiment and the pre-edge features in the NEXAFS spectra of plastocyanin are correctly predicted.
我们报告了用时间依赖密度泛函理论(TDDFT)计算的核心激发能和近边 X 射线吸收精细结构(NEXAFS)谱。已知广义梯度近似和标准混合交换相关泛函的 TDDFT 低估了核心激发能。这种失败与短电子距离处的自相互作用误差有关。研究表明,短程校正混合泛函可以将一系列分子中第一和第二核的计算核心激发能的误差降低到接近在紫外区进行更传统激发态计算中观察到的水平。用新泛函计算的 NEXAFS 谱与实验吻合得很好,并且对蓝铜蛋白的 NEXAFS 谱中的预边特征也进行了正确预测。