A CCSD(T)-Based 4-Body Potential for Water.
A CCSD(T)-Based 4-Body Potential for Water.
复制标题
基于 CCSD(T) 的四体水势。
DOI：
10.1021/acs.jpclett.1c03152
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
J. Bowman
中科院分区：
文献类型：
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作者：
Apurba Nandi;Chen Qu;P. Houston;R. Conte;Qi Yu;J. Bowman
高层次的从头计算发现，四体（4-B）相互作用是需要占近100%的总相互作用能的水分子团簇作为大的21-mer。受此启发，我们报告了一个置换不变的多项式势能面（PES）的四体相互作用。这种机器学习的PES适合于2119个独特的CCSD（T）-F12 a/haTZ 4-B相互作用能。这些来自四聚体的直接动力学计算，在300 K的MD水模拟的片段，和四聚体片段在各种水簇。PIP基础被纯化以确保PES在单体+三聚体和二聚体+二聚体解离中严格地达到零。与MB-pol势相比，用新的PES方法计算的六聚体的4-B能级与CCSD（T）的结果更接近.对较大集群的测试进一步验证了PES的高保真度。PES被证明是快速的评估，需要2.4秒的105评估的单核2.4 GHz的英特尔至强处理器，并显着更快地使用并行版本的PES。
High-level, ab initio calculations find that the 4-body (4-b) interaction is needed to account for near-100% of the total interaction energy for water clusters as large as the 21-mer. Motivated by this, we report a permutationally invariant polynomial potential energy surface (PES) for the 4-body interaction. This machine-learned PES is a fit to 2119 symmetry-unique, CCSD(T)-F12a/haTZ 4-b interaction energies. Configurations for these come from tetramer direct-dynamics calculations, fragments from an MD water simulation at 300 K, and tetramer fragments in a variety of water clusters. The PIP basis is purified to ensure that the PES goes rigorously to zero in monomer+trimer and dimer+dimer dissociations. The 4-b energies of isomers of the hexamer calculated with the new PES are shown to be in better agreement with benchmark CCSD(T) results than those from the MB-pol potential. Tests on larger clusters further validate the high-fidelity of the PES. The PES is shown to be fast to evaluate, taking 2.4 s for 105 evaluations on a single core of 2.4 GHz Intel Xeon processor, and significantly faster using a parallel version of the PES.