do Couto Paulo Cabral, Hollas Daniel, Slavíček Petr
Department of Physical Chemistry, University of Chemistry and Technology , Prague, Technická 5, Prague 6, 16628, Czech Republic.
J Chem Theory Comput. 2015 Jul 14;11(7):3234-44. doi: 10.1021/acs.jctc.5b00066.
We investigate the performance of optimally tuned range-separated hybrid functionals (OT-RSH) for modeling X-ray absorption spectra (XAS) of a benchmark set of simple molecules (water, ammonia, methane, hydrogen peroxide, hydrazine, and ethane), using time-dependent density functional theory (TDDFT). Spectra were simulated within the Path Integral based Reflection Principle methodology. Relative intensities, peak positions, and widths were compared with available experimental data. We show that the OT-RSH approach outperforms empirically parametrized functionals in terms of relative peak positions and intensities. Furthermore, we investigate the effect of geometry specific tuning where the range separation parameter is optimized for each geometry. Finally, we propose a simple correction scheme allowing for calculations of XAS on the absolute energy scale using the OT-RSH approach combined with ΔSCF/TDDFT-based calculations of core ionization energies.
我们使用含时密度泛函理论（TDDFT），研究了最优调谐的范围分离混合泛函（OT-RSH）对一组简单分子（水、氨、甲烷、过氧化氢、肼和乙烷）的基准集进行X射线吸收光谱（XAS）建模的性能。光谱是在基于路径积分的反射原理方法内模拟的。将相对强度、峰位置和宽度与现有的实验数据进行了比较。我们表明，在相对峰位置和强度方面，OT-RSH方法优于经验参数化泛函。此外，我们研究了几何特定调谐的效果，其中范围分离参数针对每种几何进行了优化。最后，我们提出了一种简单的校正方案，允许使用OT-RSH方法结合基于ΔSCF/TDDFT的核心电离能计算，在绝对能量尺度上计算XAS。
