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Updated: Jul 22, 2025

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精确计算较大分子的同质化和形态能量,使用Molpro和ORCA中的明确相关的局部合集群方法

Hans-Joachim Werner¹, Andreas Hansen²

¹Institut für Theoretische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart, Germany.

Journal of chemical theory and computation

|July 24, 2023

概括

显式相关的局部合集群方法,PNO-LCCSD(T) -F12和DLPNO-CCSD(T) -F12,进行了准确性比较. 产生了新的参考能量,为准确的电子结构计算提供了高效的计算设置.

科学领域:

计算化学计算化学
量子化学是一个量子化学.
理论化学理论化学

背景情况:

显式相关的局部合集群方法为准确的电子结构计算提供了近似值.
预测原子轨道 (PAO),对自然轨道 (PNO) 和三重自然轨道 (TNO) 是这些方法的关键组成部分.
基础集叠加效应可以阻碍准确确定完整的基础集 (CBS) 极限.

研究的目的:

为了比较Molpro的PNO-LCCSD-F12和ORCA的DLPNO-CCSD-T) F12方法中的近似值.
调查基准效应对局部合集群计算的影响.
为准确和高效的电子结构基准建立可靠的计算设置.

主要方法:

在Molpro和ORCA中PAO,PNO和TNO域选择的详细比较.
PNO-LCCSD(T) -F12和DLPNO-CCSD(T) F12在ISOL24和ACONFL基准集中的应用.
详细分析基数组效应,包括分子内基数组叠加错误.

主要成果:

明确相关的术语显著减少了基数组的依赖性和局部域错误.
对于ISOL24和ACONFL基准集的新参考能量的计算具有很高的可靠性.
识别了计算设置 (例如,PNO-LCCSD(T) -F12b/AVTZ) 以适度的计算成本进行准确的计算.

结论:

显式相关的局部合集群方法提供了准确的结果,接近CCSD (T) /CBS极限.
已经定义了用于生成可靠基准值的高效协议.
这些发现将有助于开发和评估近似电子结构方法,包括DFT和ML方法.

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