Modified Corrections for London Forces in Solid-State Density Functional Theory Calculations of Structure and Lattice Dynamics of Molecular Crystals
Modified Corrections for London Forces in Solid-State Density Functional Theory Calculations of Structure and Lattice Dynamics of Molecular Crystals
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DOI：
10.1021/jp303746a
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发表时间：
2012-06-28
影响因子：
2.9
通讯作者：
Korter, Timothy M.
中科院分区：
文献类型：
--
作者：
King, Matthew D.;Korter, Timothy M.
色散力对于定义分子晶体的晶体结构和振动势是至关重要的。因此，重要的是，包括这些力的定期密度泛函理论（DFT）计算晶格振动频率的校正。在这项研究中，DFT的伦敦型色散力的模拟的结构和太赫兹（THz）的振动光谱的色散结合固体萘和杜烯的校正项增加。修正项的参数被修改，以最好地再现实验晶体结构和太赫兹光谱。结果发现，通过调整所施加的色散力的大小的晶格尺寸的准确再现导致在最高质量的拟合计算的振动模式与观察到的太赫兹色散。提出的色散修正修正的方法提供了一种实用的方法来精确地模拟分子晶体的太赫兹光谱，占固有的系统误差所施加的计算和实验因素。
Dispersion forces are critical for defining the crystal structures and vibrational potentials of molecular crystals. It is, therefore, important to include corrections for these forces in periodic density functional theory (DFT) calculations of lattice vibrational frequencies. In this study, DFT was augmented with a correction term for London-type dispersion forces in the simulations of the structures and terahertz (THz) vibrational spectra of the dispersion-bound solids naphthalene and durene. The parameters of the correction term were modified to best reproduce the experimental crystal structures and THz spectra. It was found that the accurate reproduction of the lattice dimensions by adjusting the magnitude of the applied dispersion forces resulted in the highest-quality fit of the calculated vibrational modes with the observed THz absorptions. The method presented for the modification of the dispersion corrections provides a practical approach to accurately simulating the THz spectra of molecular crystals, accounting for inherent systematic errors imposed by computational and experimental factors.