Low‐lying energy isomers and global minima of aqueous nanoclusters: Structures and spectroscopic features of the pentagonal dodecahedron (H2O)20 and (H3O)+(H2O)20
Low‐lying energy isomers and global minima of aqueous nanoclusters: Structures and spectroscopic features of the pentagonal dodecahedron (H2O)20 and (H3O)+(H2O)20
复制标题
水性纳米团簇的低能异构体和全局极小值：五角十二面体(H2O)20和(H3O)+(H2O)20的结构和光谱特征
DOI：
10.1002/cjce.21645
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发表时间：
2012
影响因子：
2.1
通讯作者：
S. Xantheas
中科院分区：
文献类型：
--
作者：
S. Xantheas
我们依赖于一个层次的方法来确定低躺异构体和相应的全局最小值的五角十二面体（H2O）20和H3 O+（H2O）20纳米团簇。使用经典相互作用势进行异构体的初始筛选，即可转移相互作用4-位点势（TIP 4P）、用于（H2O）20的Thole型灵活模型版本2.0（TTM 2-F）和2.1（TTM2.1-F）以及用于H3 O+（H2O）20的各向异性位点势（ASP）。随后在密度泛函理论（DFT）中用Becke-3-参数Lee-Yang-Parr（B3 LYP）泛函和二阶Moller-Plesset微扰（MP2）理论水平对用这些势获得的纳米网络进行了改进。对于五角十二面体（H2O）20，发现DFT（B3 LYP）和MP2产生相同的全局最小值。然而，对于H3 O+（H2O）20簇来说，情况并非如此，与DFT（B3 LYP）相比，MP2为全局最小值产生了不同的网络。H3 O+（H2O）20的低位网络对应于在纳米团簇表面上具有9个“自由”OH键和水合氢离子的结构。在OH伸缩（“指纹”）区域中进一步分析了各种网络的IR光谱，并将各种谱带分配给底层氢键网络的结构排列。© 2012加拿大化学工程学会
We rely on a hierarchical approach to identify the low-lying isomers and corresponding global minima of the pentagonal dodecahedron (H2O)20 and the H3O+(H2O)20 nanoclusters. Initial screening of the isomers is performed using classical interaction potentials, namely the Transferable Interaction 4-site Potential (TIP4P), the Thole-Type Flexible Model, versions 2.0 (TTM2-F) and 2.1 (TTM2.1-F) for (H2O)20 and the Anisotropic Site Potential (ASP) for H3O+(H2O)20. The nano-networks obtained with those potentials were subsequently refined at the density functional theory (DFT) with the Becke-3-parameter Lee–Yang–Parr (B3LYP) functional and at the second order Moller–Plesset perturbation (MP2) levels of theory. For the pentagonal dodecahedron (H2O)20 it was found that DFT (B3LYP) and MP2 produced the same global minimum. However, this was not the case for the H3O+(H2O)20 cluster, for which MP2 produced a different network for the global minimum when compared to DFT (B3LYP). The low-lying networks of H3O+(H2O)20 correspond to structures having 9 ‘free’ OH bonds and the hydronium ion on the surface of the nanocluster. The IR spectra of the various networks are further analysed in the OH stretching (‘fingerprint’) region and the various bands are assigned to structural arrangements of the underlying hydrogen bonding network. © 2012 Canadian Society for Chemical Engineering