Mihailovs Igors, Belobrovko Ekaterina, Bundulis Arturs, Bocharov Dmitry V, Kotomin Eugene A, Rutkis Martins
Institute of Solid State Physics, University of Latvia, 8 Ķengaraga St., LV-1063 Riga, Latvia.
Institute of Chemistry and Chemical Technology, Faculty of Natural Sciences and Technology, Riga Technical University, 3 Paula Valdena St., LV-1048 Riga, Latvia.
Nanomaterials (Basel). 2025 Aug 23;15(17):1302. doi: 10.3390/nano15171302.
There has been considerable scientific interest in third-order nonlinear optical materials for photonic applications. In particular, materials exhibiting a strong electronic optical Kerr effect serve as essential components in the ultrafast nonlinear photonic devices and are instrumental in the development of all-optical signal processing technologies. Therefore, the accurate prediction of material-relevant properties, such as second hyperpolarizabilities, remains a key topic in the search for efficient photonic materials. However, the field standards in quantum chemical computation are still inconsistent, as studies often lack a firm statistical foundation. This work presents a comprehensive in silico investigation based on multiple full-factorial experiments, aiming to clarify the strengths and limitations of various computational approaches. Our results indicate that the coupled-cluster approach at the CCSD level in its current response-equation implementations is not yet able to outperform the range-separated hybrid density functionals, such as LC-BLYP(0.33). The exceptional performance of the specifically tailored basis set Sadlej-pVTZ is also described. Not only was the presence of diffuse functions found to be mandatory, but also adding ample polarization functions is shown to be inefficient resource-wise. HF/Sadlej-pVTZ is proven to be reliable enough to use in molecular screening. Meta functionals are confirmed to produce poorly consistent results, and specific guidelines for constructing range-separated functionals for polarizability calculations are drawn out. Additionally, it was shown that many of the contemporary solvation models exhibit significant limitations in accurately capturing nonlinear optical properties. Therefore, further refinement in the current methods is pending. This extends to the statistical description as well: the mean absolute deviation descriptor is found to be deficient in rating various computational methods and should rather be replaced with the parameters of the linear correlation (the slope, the intercept, and the R).
对于用于光子应用的三阶非线性光学材料，一直存在着相当大的科学兴趣。特别是，表现出强电子光学克尔效应的材料是超快非线性光子器件的关键组件，并且在全光信号处理技术的发展中发挥着重要作用。因此，准确预测与材料相关的性质，如二阶超极化率，仍然是寻找高效光子材料的关键课题。然而，量子化学计算中的领域标准仍然不一致，因为研究往往缺乏坚实的统计基础。这项工作基于多个全因子实验进行了全面的计算机模拟研究，旨在阐明各种计算方法的优缺点。我们的结果表明，当前响应方程实现中的CCSD水平的耦合簇方法尚无法超越范围分离的混合密度泛函，如LC-BLYP(0.33)。还描述了专门定制的基组Sadlej-pVTZ的卓越性能。不仅发现漫射函数的存在是必不可少的，而且增加大量极化函数在资源利用方面也被证明是低效的。HF/Sadlej-pVTZ被证明足够可靠，可用于分子筛选。元泛函被证实产生的结果一致性较差，并制定了用于极化率计算的构建范围分离泛函的具体指导方针。此外，可以看出许多当代溶剂化模型在准确捕捉非线性光学性质方面存在显著局限性。因此，目前的方法有待进一步完善。这也延伸到统计描述：发现平均绝对偏差描述符在评估各种计算方法时存在缺陷，而应该用线性相关的参数（斜率、截距和R）来代替。
