Plasser Felix, Mewes Stefanie A, Dreuw Andreas, González Leticia
Institute for Theoretical Chemistry, Faculty of Chemistry, University of Vienna , Währingerstrasse 17, 1090 Vienna, Austria.
Interdisciplinary Center for Scientific Computing, Ruprecht-Karls-University , Im Neuenheimer Feld 205 A, 69120 Heidelberg, Germany.
J Chem Theory Comput. 2017 Nov 14;13(11):5343-5353. doi: 10.1021/acs.jctc.7b00718. Epub 2017 Oct 17.
High-level multireference computations on electronically excited and charged states of tetracene are performed, and the results are analyzed using an extensive wave function analysis toolbox that has been newly implemented in the Molcas program package. Aside from verifying the strong effect of dynamic correlation, this study reveals an unexpected critical influence of the atomic orbital basis set. It is shown that different polarized double-ζ basis sets produce significantly different results for energies, densities, and overall wave functions, with the best performance obtained for the atomic natural orbital (ANO) basis set by Pierloot et al. Strikingly, the ANO basis set not only reproduces the energies but also performs exceptionally well in terms of describing the diffuseness of the different states and of their attachment/detachment densities. This study, thus, not only underlines the fact that diffuse basis functions are needed for an accurate description of the electronic wave functions but also shows that, at least for the present example, it is enough to include them implicitly in the contraction scheme.
对并四苯的电子激发态和带电态进行了高水平的多参考计算，并使用Molcas程序包中新实现的广泛波函数分析工具箱对结果进行了分析。除了验证动态相关的强烈影响外，本研究还揭示了原子轨道基组出人意料的关键影响。结果表明，不同的极化双ζ基组在能量、密度和整体波函数方面产生显著不同的结果，Pierloot等人的原子自然轨道（ANO）基组表现最佳。引人注目的是，ANO基组不仅能重现能量，而且在描述不同状态的弥散性及其附着/脱离密度方面也表现出色。因此，本研究不仅强调了准确描述电子波函数需要弥散基函数这一事实，还表明，至少对于当前示例，在收缩方案中隐式包含它们就足够了。
