Direct Elucidation of the Vibrationally Averaged Structure of Benzene: A Path Integral Molecular Dynamics Study
Direct Elucidation of the Vibrationally Averaged Structure of Benzene: A Path Integral Molecular Dynamics Study
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直接阐明苯的振动平均结构：路径积分分子动力学研究
DOI：
10.1021/acs.jpca.2c07197
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Nagashima Umpei
中科院分区：
文献类型：
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作者：
Udagawa Taro;Tanaka Hikaru;Hirano Tsuneo;Kuwahata Kazuaki;Tachikawa Masanori;Baba Masaaki;Nagashima Umpei
采用路径积分分子动力学（PIMD）方法对C6 H6、C6 D 6和C6 T6分子进行了模拟，直接估算了C-H（D，T）键长在主轴面上的投影分布.由于势能曲线的非谐性，PIMD模拟得到的原始C-H（D，T）键长的平均值顺序为：RC-H键> RC-D键> RC-T键。然而，预计的C-H（D，T）键长几乎与Hirano等人[J. Mol.结构2021，1243，130537]。我们的PIMD模拟直接和强有力地支持Hirano等人对实验观察结果的解释，即C6 H6和C6 D 6的C-H（D）键长几乎相同。PIMD模拟还预测了C6 T6与C6 H（D）6相同的投影键长。除了以前的本地模式分析，目前的PIMD模拟预测，苯同位素，振动平均结构是平面的，但非平坦的。
Path integral molecular dynamics (PIMD) simulations for C6H6, C6D6, and C6T6have been carried out to directly estimate the distribution of projected C–H(D,T) bond lengths onto the principal axis plane. The average values of raw C–H(D,T) bond lengths obtained from PIMD simulations are in the order of ⟨RC–H⟩ > ⟨RC–D⟩ > ⟨RC–T⟩ due to the anharmonicity of the potential energy curve. However, the projected C–H(D,T) bond lengths are almost the same as those reported by Hirano et al. [J. Mol. Struct.2021,1243, 130537]. Our PIMD simulations directly and strongly support the explanation by Hirano et al. for the experimental observations that almost the same projected C–H(D) bond lengths are found for C6H6and C6D6. The PIMD simulations also predicted the same projected bond lengths for C6T6as those of C6H(D)6. In addition to the previous local mode analysis, the present PIMD simulations predicted, for benzene isotopologues, that the vibrationally averaged structure is planar but non-flat.