Validation of dispersion-corrected density functional theory approaches for ionic liquid systems.
Validation of dispersion-corrected density functional theory approaches for ionic liquid systems.
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DOI：
10.1021/jp805306u
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发表时间：
2008-08
期刊：
影响因子：
--
通讯作者：
Stefan Zahn;B. Kirchner
中科院分区：
文献类型：
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作者：
Stefan Zahn;B. Kirchner
几个一般梯度近似，Meta一般梯度近似，和混合泛函的性能进行测试对Møller-Plesset微扰理论二阶离子液体系统。此外，两个色散校正的方法（添加货车范德华力的1/r（6）项和采用色散校正的原子中心色散赝势）进行了研究。对于1-丁基-3-甲基咪唑阳离子，忽略分散导致不同的结构稳定性趋势。两种密度泛函修正方案的应用大大改善了结果。研究几个1-丁基-3-甲基咪唑二酰胺离子对显示平均绝对偏差Møller-Plesset微扰理论为35.7 kJ/mol的Hartree-Fock和高达33.2 kJ/mol的密度泛函理论方法。色散校正方法将平均绝对偏差降低到小于10 kJ/mol。比较1-乙基-3-甲基咪唑鎓二酰胺离子对与Diels-Alder离析物（环戊二烯和丙烯酸甲酯）的加合物显示出与离子对类似的能量差异。此外，发现Hartree-Fock方法（平均绝对偏差：190 pm）和密度泛函理论（平均绝对偏差高达178 pm）的分子间距离的几何形状的大偏差，而分散校正的方法的平均绝对偏差小于50 pm。
The performance of several general gradient approximation, meta general gradient approximation, and hybrid functionals is tested against Møller-Plesset perturbation theory second-order for ionic liquid systems. Additionally, two dispersion-corrected approaches (addition of van der Waals forces by a 1/r(6) term and employing a dispersion-corrected atom-center dispersion pseudopotential) were studied. For the 1-butyl-3-methylimidazolium cation neglecting dispersion results in different trends for structural stabilities. The two applied correction schemes for density functional theory improve the results tremendously. Investigating several 1-butyl-3-methylimidazolium dicianamide ion pairs shows a mean absolute deviation from Møller-Plesset perturbation theory of 35.7 kJ/mol for Hartree-Fock and up to 33.2 kJ/mol for the density functional theory methods. The dispersion-corrected methods reduce the mean absolute deviation to less than 10 kJ/mol. Comparing adducts of the 1-ethyl-3-methylimidazolium dicianamide ion pair with Diels-Alder educts (cyclopentadiene and methylacrylate) shows similar energetic differences as for the ion pairs. Furthermore large deviations in geometries for the intermolecular distances were found for the Hartree-Fock approach (mean absolute deviation: 190 pm) and density functional theory (mean absolute deviation up to 178 pm) while for the dispersion-corrected methods the mean absolute deviation is less than 50 pm.