Modeling the Interactions Between Polyoxometalates and Their Environment
Modeling the Interactions Between Polyoxometalates and Their Environment
复制标题
DOI：
10.1002/jcc.21894
复制
发表时间：
2011-11-30
影响因子：
3
通讯作者：
Bridgeman, Adam J.
中科院分区：
文献类型：
--
作者：
Courcot, Blandine;Bridgeman, Adam J.
为了开发适合多金属氧酸盐（POMs）和有机阳离子的力场，选择默克分子力场94x （MMFF94x）来描述POMs合成中使用的反离子，并将其与我们针对ii型POMs优化的力场相结合，其中静电和范德华相互作用包括在电位中。力场的不可转移性是众所周知的，为了克服这一限制，引入并优化了电荷缩放因子（SF）来调整POMs力场参数，使其适应MMFF94x。对MMFF94x/POMFF-II混合力场进行了优化，并在七种钼酸盐的不同簇上进行了测试。为了验证我们的混合力场与分子力学（MM）后得到的结果的比较，在最小的感兴趣的系统上进行了密度泛函（DFT）计算的几何优化。这使得研究不同功能的准确性，特别是对氢键的描述成为可能。结果在结构精度方面是有希望的。MM几何优化可以用于小型POM集群，与DFT相当好地竞争。当量子方法由于所研究系统的大小而大大增加计算成本时，可以使用MM，但有一点保留，即即使引入的电荷SF改善了力场的性能，在进一步的研究中可能需要进一步优化用于原子电荷的非键项和模型。(C) 2011 Wiley期刊公司[J] .计算机工程学报，2011,32 (3):343 - 343
To develop a force field suitable both for polyoxometalates (POMs) and organic cations, the Merck molecular force field 94x (MMFF94x) has been selected to describe the counterions used in POMs synthesis and has been combined with our force field optimized for type-II POMs with electrostatic and Van der Waals interactions included in the potential. Nontransferability of force fields is well-known and, to overcome this limitation, a charge-scaling factor (SF) has been introduced and optimized to tune the POMs force field parameters and adapt them to MMFF94x. The mixed MMFF94x/POMFF-II force field has been optimized and tested on different clusters based on hepta-molybdate. To validate our mixed force field comparison of the results obtained after molecular mechanics (MM), geometry optimizations with density-functional (DFT) calculations have been performed on the smallest system of interest. This has enabled a study of the accuracy of different functionals, especially on the description of hydrogen bonding, to be made. Results are promising in terms of structural accuracy. MM geometry optimization can be used on small POM clusters, competing reasonably well with DFT. When quantum approaches increase considerably the computational cost because of the size of the system studied, MM can be used, with the small reservation that even if the charge SF introduced improves the performance of the force field, further optimizations of the nonbonded term and the model used for the atomic charges may be necessary in further studies. (C) 2011 Wiley Periodicals, Inc. J Comput Chem 32: 3143-3153, 2011