高精度外推从头算热化学。IV. 一种提高计算效率的改进方法。
High-accuracy extrapolated ab initio thermochemistry. IV. A modified recipe for computational efficiency.
作者信息
Thorpe James H, Lopez Chris A, Nguyen Thanh Lam, Baraban Joshua H, Bross David H, Ruscic Branko, Stanton John F
机构信息
The Quantum Theory Project, Department of Chemistry, The University of Florida, Gainesville, Florida 32611, USA.
Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, USA.
出版信息
J Chem Phys. 2019 Jun 14;150(22):224102. doi: 10.1063/1.5095937.
A number of economical modifications to the high-accuracy extrapolated ab initio thermochemistry (HEAT) model chemistry are evaluated. The two resulting schemes, designated as mHEAT and mHEAT+, are designed for efficient and pragmatic evaluation of molecular energies in systems somewhat larger than can be practically studied by the unapproximated HEAT scheme. It is found that mHEAT+ produces heats of formation with nearly subchemical (±1 kJ/mol) accuracy at a substantially reduced cost relative to the full scheme. Total atomization energies calculated using the new thermochemical recipes are compared to the results of the HEAT-345(Q) model chemistry, and enthalpies of formation for the three protocols are also compared to Active Thermochemical Tables. Finally, a small selection of transition states is studied using mHEAT and mHEAT+, which illuminates some interesting features of reaction barriers and serves as an initial benchmark of the performance of these model chemistries for chemical kinetics applications.
对高精度外推从头算热化学（HEAT）模型化学进行了一些经济性修正评估。由此产生的两种方案，分别命名为mHEAT和mHEAT+，旨在高效且实用地评估比未近似的HEAT方案实际可研究的系统稍大一些的分子能量。研究发现，mHEAT+生成的生成热具有近乎亚化学级（±1 kJ/mol）的精度，且相对于完整方案成本大幅降低。使用新热化学方法计算的总原子化能与HEAT-345(Q)模型化学的结果进行了比较，并且三种方案的生成焓也与活性热化学表进行了比较。最后，使用mHEAT和mHEAT+研究了一小部分过渡态，这揭示了反应势垒的一些有趣特征，并作为这些模型化学在化学动力学应用中性能的初步基准。
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