Efficient Molecular Dynamics Simulations of Multiple Radical Center Systems Based on the Fragment Molecular Orbital Method
Efficient Molecular Dynamics Simulations of Multiple Radical Center Systems Based on the Fragment Molecular Orbital Method
复制标题
基于碎片分子轨道法的多自由基中心体系高效分子动力学模拟
DOI：
10.1021/jp507726m
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发表时间：
2014
期刊：
影响因子：
2.9
通讯作者：
and Mark S. Gordon
中科院分区：
文献类型：
--
作者：
Hiroya Nakata;Michael W. Schmidt;Dmitri G. Fedorov. Kazuo Kitaura;Shinichiro Nakamura;and Mark S. Gordon
基于碎片分子轨道（FMO）理论，对具有多个开壳分子的体系，建立并实现了限制开壳Hartree-Fock （ROHF）方法的全解析能量梯度。将解析的ROHF能量梯度与相应的数值梯度进行了精度比较，说明了解析梯度的精度。ROHF分析梯度用于执行不寻常的开壳系统，液氧和氧氮混合物的分子动力学模拟。这些分子动力学模拟提供了一些关于三重态氧分子如何相互作用的见解。时间表明，该方法可以在6小时内计算出含有4000个原子的体系的能量梯度。因此，FMO-ROHF方法将用于研究具有多个开壳层的体系。
The fully analytic energy gradient has been developed and implemented for the restricted open-shell Hartree–Fock (ROHF) method based on the fragment molecular orbital (FMO) theory for systems that have multiple open-shell molecules. The accuracy of the analytic ROHF energy gradient is compared with the corresponding numerical gradient, illustrating the accuracy of the analytic gradient. The ROHF analytic gradient is used to perform molecular dynamics simulations of an unusual open-shell system, liquid oxygen, and mixtures of oxygen and nitrogen. These molecular dynamics simulations provide some insight about how triplet oxygen molecules interact with each other. Timings reveal that the method can calculate the energy gradient for a system containing 4000 atoms in only 6 h. Therefore, it is concluded that the FMO-ROHF method will be useful for investigating systems with multiple open shells.