Barrier for the H2CO --> H2+ CO reaction: A discrepancy between high-level electronic structure calculations and experiment
Barrier for the H2CO --> H2+ CO reaction: A discrepancy between high-level electronic structure calculations and experiment
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H2CO 的势垒 --> H2 CO 反应：高级电子结构计算与实验之间的差异
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
B. Garrett
中科院分区：
文献类型：
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作者：
D. Feller;M. Dupuis;B. Garrett
用扩展基组计算和各种中高精度相关恢复技术研究了甲醛与H_2+CO的单分子解离反应。其中包括二阶和四阶微扰理论，多参考组态相互作用波函数，微扰三重和全迭代三重耦合团簇理论，以及全组态相互作用波函数的估算。通过将总能量外推到完全基组极限来评估电子结构方法的固有误差。考虑零点振动效应，我们对势垒高度的最佳估计为81.90±0.3kcal/ ，比实验值79.2±0.8kcal/ 大了近3kcal/mo1。这一估计包括对有限基集截断(在五元Zeta水平上可以忽略)、更高阶关联恢复、核/价关联和标量相对论效应的影响的修正。用同样的理论方法，我们估计……
The unimolecular dissociation of formaldehyde to H2+CO was studied using extended basis set calculations and a variety of medium-to-high accuracy correlation recovery techniques. These included second and fourth order perturbation theory, multireference configuration interaction wave functions, coupled cluster theory with perturbative triples and full iterative triples, and estimated full configuration interaction wave functions. The intrinsic error of the electronic structure methods was assessed by extrapolating total energies to the complete basis set limit. Our best estimate of the barrier height, including zero point vibrational effects, is 81.9±0.3 kcal/mol, almost 3 kcal/mol larger than the experimental value of 79.2±0.8 kcal/mol. This estimate includes corrections for the effects of finite basis set truncation (which is negligible at the quintuple zeta level), higher order correlation recovery, core/valence correlation, and scalar relativistic effects. Using the same theoretical approach, we estim...