关于计算的部分电荷对基数和 (交换) 相关性处理的敏感性
1Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Reḥovot, Israel.
计算部分电荷对基本集和方法敏感. 半经验方法接近黄金标准的准确性,全球混合物是Hartree-Fock交换的最佳选择. 根据收费的定义,基准集的收率有所不同.
科学领域:
- 计算化学是一种计算化学.
- 量子化学是一种量子化学.
- 化学信息学 化学信息学
背景情况:
- 部分电荷是化学和生物学的基础.
- 存在许多计算定义,导致不一致.
- 之前的工作将定义缩小到离子性的三个主要组成部分.
研究的目的:
- 调查基础集和计算方法对部分电费计算的影响.
- 评估各种部分电荷定义,包括QTAIM,Hirshfeld和NPA.
- 确定最佳的计算策略,以准确地确定部分电荷.
主要方法:
- 评估依赖于1个粒子基础的集合.
- 检查了波函数理论 (WFT) 方法的相关性处理.
- 分析了密度函数理论 (DFT) 方法的交换相关函数.
- 与单打,双打和三打 (CCSD(T)) "黄金标准"结合集群的结果进行比较.
主要成果:
- 半经验式双杂交物非常接近CCSD的准确性.
- MP2 (第二阶MøllerPlesset扰动理论) 显示错误补偿,相对于CCSD (与单元和双元相结合的集群) 的表现优于CCSD (单元和双元).
- 非本地相关性至关重要,特别是在具有重大非本地交换的情况下.
- 具有20%-30%的Hartree-Fock交换的全球混合物是最优的.
- 对赫什菲尔德和GAPT收费来说,增强的三倍泽塔基数组就足够了;QTAIM和NPA需要更大的基数组,并且与Hartree-Fock的趋同速度较慢.
- 三倍校正 (CCSD(T) -CCSD) 加快了基准集的收.
结论:
- 计算策略显著影响部分电荷计算.
- 对于不同的电荷定义,建议使用特定的方法和基础集.
- 了解这些依赖关系是可靠计算化学结果的关键.
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