Cheap but accurate calculation of chemical reaction rate constants from ab initio data, via system-specific, black-box force fields.
Cheap but accurate calculation of chemical reaction rate constants from ab initio data, via system-specific, black-box force fields.
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DOI：
10.1063/1.4979712
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发表时间：
2017-04
期刊：
影响因子：
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通讯作者：
Julien Steffen;B. Hartke
中科院分区：
文献类型：
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作者：
Julien Steffen;B. Hartke
基于最近发表的量子力学导出力场（QMDFF）及其经验价键扩展EVB-QMDFF，现在可以以基本上黑箱的方式为任何给定的基元反应步骤生成可靠的势能面。这需要在反应路径附近的一组有限的和预定义的参考数据，并生成反应路径上和反应路径外的参考势能面的精确近似。这种中间表示可用于生成反应速率数据，其准确性和可靠性远远优于基于过渡态理论（TST）或其变分扩展（VTST）的传统方法，即使这些包括复杂的隧道校正。然而，参考水平的额外费用仍然很小。我们证明了这三个任意选择的例子反应。
Building on the recently published quantum-mechanically derived force field (QMDFF) and its empirical valence bond extension, EVB-QMDFF, it is now possible to generate a reliable potential energy surface for any given elementary reaction step in an essentially black box manner. This requires a limited and pre-defined set of reference data near the reaction path and generates an accurate approximation of the reference potential energy surface, on and off the reaction path. This intermediate representation can be used to generate reaction rate data, with far better accuracy and reliability than with traditional approaches based on transition state theory (TST) or variational extensions thereof (VTST), even if those include sophisticated tunneling corrections. However, the additional expense at the reference level remains very modest. We demonstrate all this for three arbitrarily chosen example reactions.