激进的加法反应:层次的ab initio基准和dft性能研究
Yuman Hordijk1, Marco Dalla Tiezza1, Daniela Rodrigues Silva1
1Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute for Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam De Boelelaan 1108, 1081, HZ Amsterdam, The Netherlands.
概括
这项研究对激素加法反应的初始方法进行了基准测试,建立了高精度的参考数据. 然后它评估了98个密度函数理论 (DFT) 近似,确定了反应障碍和能量的最佳表现者.
科学领域:
- 计算化学的计算化学
- 量子化学 是一个量子化学.
- 理论化学 理论化学
背景情况:
- 准确的反应能量和机制的理论预测在化学中至关重要.
- 对不和碳化合物的激进添加反应是具有广泛影响的基本过程.
- 以前的研究通常依赖于不那么严格的计算方法,限制了预测准确度.
研究的目的:
- 对气相激素加法反应进行一个层次的初始基准研究.
- 为了建立涉及甲基,氨基,基和硫甲基与乙烯和乙烯的反应的高精度参考数据.
- 根据这个基准数据,评估广泛的密度函数理论 (DFT) 近似的性能.
主要方法:
- 采用一系列的ab initio方法 (HF,MP2,CCSD,CCSD(T)) 和宁基础集 ((aug) -cc-pVDZ, (aug) -cc-pVTZ, (aug) -cc-pVQZ).
- 在HF计算中利用准限制轨道 (QRO) 参考波函数来减轻旋转污染.
- 将结果推算到完整基准集 (CBS) 极限以获得更高的准确性.
- 对98个DFT近似进行了评估,以确定它们能够复制基准反应障碍,能量和几何形状的能力.
主要成果:
- 在QRO-CCSD (T) /CBS+层面上,初始计算趋于0.0-3.4 kcal mol-1的方法和0.0-1.0 kcal mol-1的基础集.
- 确定了几个具有0.8-1.0 kcal mol-1的平均绝对误差 (MAE) 的DFT函数,用于反应障碍和能量.
- 性能最好的DFT函数包括MN12-SX,CAM-B3LYP,M06-2X,BMK和OLYP.
- 这些顶级DFT函数精确地复制了关键的几何参数,平均偏离基准2%的平均偏差.
结论:
- 该研究提供了一个强大的基准数据集,用于使用高级ab initio理论的激进加法反应.
- 特定的DFT函数在预测反应能量和几何学方面具有很高的准确性,为计算研究提供了可靠的替代方案.
- 这些发现指导了选择适当的DFT方法,用于未来对类似化学系统的研究.
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