Benchmark Relative Energies for Large Water Clusters with the Generalized Energy-Based Fragmentation Method
Benchmark Relative Energies for Large Water Clusters with the Generalized Energy-Based Fragmentation Method
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使用基于能量的广义破碎方法对大型水团簇的相对能量进行基准测试
DOI：
10.1021/acs.jctc.7b00284
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
Li Shuhua
中科院分区：
文献类型：
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作者：
Yuan D;an;Li Yunzhi;Ni Zhigang;Pulay Peter;Li Wei;Li Shuhua
采用广义能量碎裂（GEBF）方法，在完全基组（CBS）极限下，采用非迭代三重激发耦合单团簇和双团簇（CCSD（T））和二阶Møller-Plesset微扰理论（MP2）计算了水分子团簇（H2O）n（n= 32，64）的相对能量.在这里，大的水簇被选择为从液态水的分子动力学（MD）模拟中采样的代表性结构。我们的计算表明，GEBF方法是能够提供高精度的相对能量，这些水团簇的成本效益的方式。我们证明了GEBF-MP2/CBS与GEBF-CCSD（T）/CBS对这些水分子团簇的相对能量非常一致。以GEBF-CCSD（T）/CBS相对能量为基准，我们评估了几种广泛用于液体和水溶液从头算分子动力学模拟的理论方法的性能。这些方法包括密度泛函理论（DFT）与许多不同的泛函，MP2和密度泛函紧束缚（第三代，简称DFTB 3）。我们发现MP2/aug-cc-pVDZ和几种密度泛函方法（如LC-ωPBE-D3和ω B 97 XD）在aug-cc-pVTZ基组上可以对这些水分子团簇提供满意的描述。一些广泛使用的泛函（如B3 LYP，PBE 0）和DFTB 3是不够准确的描述大的水团簇的相对能量。虽然DFT方法的基组依赖性比初始电子相关方法小，但在水分子团簇或水溶液的理论研究中，我们推荐使用几个最佳泛函和大基组（至少aug-cc-pVTZ）的组合。
The generalized energy-based fragmentation (GEBF) method has been applied to investigate relative energies of large water clusters (H2O)n(n= 32, 64) with the coupled-cluster singles and doubles with noniterative triple excitations (CCSD(T)) and second-order Møller–Plesset perturbation theory (MP2) at the complete basis set (CBS) limit. Here large water clusters are chosen to be representative structures sampled from molecular dynamics (MD) simulations of liquid water. Our calculations show that the GEBF method is capable of providing highly accurate relative energies for these water clusters in a cost-effective way. We demonstrate that the relative energies from GEBF-MP2/CBS are in excellent agreement with those from GEBF-CCSD(T)/CBS for these water clusters. With the GEBF-CCSD(T)/CBS relative energies as the benchmark results, we have assessed the performance of several theoretical methods widely used forab initioMD simulations of liquids and aqueous solutions. These methods include density functional theory (DFT) with a number of different functionals, MP2, and density functional tight-binding (the third generation, DFTB3 in short). We find that MP2/aug-cc-pVDZ and several DFT methods (such as LC-ωPBE-D3 and ωB97XD) with the aug-cc-pVTZ basis set can provide satisfactory descriptions for these water clusters. Some widely used functionals (such as B3LYP, PBE0) and DFTB3 are not accurate enough for describing the relative energies of large water clusters. Although the basis set dependence of DFT is less than that ofab initioelectron correlation methods, we recommend the combination of a few best functionals and large basis sets (at least aug-cc-pVTZ) in theoretical studies on water clusters or aqueous solutions.