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基准测试振动二次扰动理论双极时刻的计算及其与电子密度错误的相关性使用密度函数理论

Dylan Fowler¹, Kurt R Brorsen¹

¹Department of Chemistry, University of Missouri, Columbia, Missouri, USA.

Journal of computational chemistry

|December 24, 2025

概括

使用DFT-VPT2计算具有振动效应的分子二极点时刻,比标准的DFT方法提供了有限的精度改进. 这项大规模的研究表明,包括振动校正通常是不必要的准确的二极点时刻预测.

科学领域:

计算化学计算化学
量子化学是一个量子化学.
分子建模分子建模

背景情况:

二极时是重要的电子特性,在化学和物理中广泛应用.
众所周知,振动效应会影响分子双极时刻,但它们对大规模密度函数理论 (DFT) 计算的影响仍未得到充分研究.

研究的目的:

通过振动二次扰动理论 (VPT2) 将振动效应纳入DFT计算小分子二极矩的有效性评估.
为了评估计算的二极点和电子密度错误之间的相关性.

主要方法:

用DFT与VPT2 (DFT-VPT2) 和标准DFT相结合的DFT计算了125个小分子的二极点.
采用了aug-cc-PVTZ基础集和各种交换相关函数的平均结果.
使用先前研究的密度配置文件量化电子密度错误.

主要成果:

与标准的DFT相比,DFT-VPT2计算的准确性略有改善,绝对平均值,绝对平均值,平均百分比和根的平均平方值的误差减少.
计算的二极子时刻的精度与电子密度误差之间的相关性被发现是微弱的 (R2 < 0.5).

结论:

在双极时刻的DFT计算中包括VPT2振动效应只能提供有限的精度增强.
二极矩不是评估电子密度分布错误的可靠指标.
对于大多数应用,DFT双极矩计算中省略VPT2校正被认为是不必要的,因为精度的增长很小.

关键词:

密度函数理论密度函数理论双极时刻是指双极时刻的时间.旋转光谱学是一种旋转光谱学.振动扰动理论振动扰动理论

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