Assessment of range-separated exchange functionals and nonempirical functional tuning for calculating the static second hyperpolarizabilities of streptocyanines

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• 作者：Chao Wang ; Yizhong Yuan and Xiaohui Tian
• 刊名：Journal of Computational Chemistry
• 出版年：2017
• 出版时间：April 5, 2017
• 年：2017
• 卷：38
• 期：9
• 页码：594-600
• 全文大小：467K
• ISSN：1096-987X

文摘

DFT method can severely overestimate the response properties for π-conjugation systems. The range-separated exchange and recently developed optimal IP-tuning process are evaluated on the prediction of static second hyperpolarizabilities of streptocyanines of increasing molecular length. The finite field results have shown that the exact exchange at midium and long distance can relieve only a part of the overshooting but still beyond satisfaction. The exact exchange at short distance has the oppsite effects showing the failure of converntional hGGA. The optimal tuned range-separated exchange functionals show little improvements performing worse than the default ones. Importantly, the electronic structure–property relationship, bond order alternation-γ, is not well established with DFT method.