Accurate Relative Energies and Binding Energies of Large Ice-Liquid Water Clusters and Periodic Structures
Accurate Relative Energies and Binding Energies of Large Ice-Liquid Water Clusters and Periodic Structures
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大冰-液态水团簇和周期性结构的精确相对能量和结合能
DOI：
10.1021/acs.jpca.7b03376
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Li Shuhua
中科院分区：
文献类型：
--
作者：
Zhang Lei;Li Wei;Fang Tao;Li Shuhua
相对能量和结合能是决定冰和水的各种分子性质的关键参数。我们发展了一种新的有效的方法来计算体冰-液态水系统的能量。在这项工作中，10个冰-液体144-MERS和10个周期冰-液体(H2O)64系统是从分子动力学模拟冰水晶体的熔化过程。在广义能量碎裂方法的框架下，在密度泛函理论(DFT)、显式关联二阶M&Plesset微扰理论(MP2-F12)和具有非迭代三重修正的耦合团簇单双星[CCSD(T)-F12b]的水平上对它们进行了研究。结果表明，在冰的融化过程中，非共价相互作用的变化对这些体系的密度泛函理论和电子相关方法的性能有很大影响。不同的密度泛函方法对冰和冰液混合结构的预测结果截然不同，但对纯液体结构的预测结果相似。这也解释了为什么许多基于DFT的模拟导致冰和液态水的密度不准确。CCSD(T)-F12b的计算结果表明，MP2-F12方法获得了令人满意的结果，可望用于冰晶相变的模拟。
Relative energies and binding energies are crucial quantities that determine various molecular properties of ice and water. We developed a new effective method to compute those energies of bulk ice–liquid water systems. In this work, ten ice–liquid 144-mers and ten periodic ice–liquid (H2O)64systems are taken from the molecular dynamics simulations in the melting process of ice-Ih crystals. They are investigated at the levels of density functional theory (DFT), explicitly correlated second-order Møller–Plesset perturbation theory (MP2-F12), and coupled-cluster singles and doubles with noniterative triples corrections [CCSD(T)-F12b] in the framework of generalized energy-based fragmentation approach. Our results show that the changing of noncovalent interactions significantly influences the performances of DFT and electron correlation methods for those systems in the melting process of ice. Various DFT methods predict quite different results for ice and mixed ice–liquid structures but give similar results for pure liquid ones. It also explains why many DFT-based simulations lead to inaccurate densities of ice and liquid water. The CCSD(T)-F12b results suggest that the MP2-F12 method provides satisfactory results and is expected to be employed to simulate the phase transitions of ice crystal.