Comparison of some dispersion-corrected and traditional functionals with CCSD(T) and MP2 ab initio methods: Dispersion, induction, and basis set superposition error
Comparison of some dispersion-corrected and traditional functionals with CCSD(T) and MP2 ab initio methods: Dispersion, induction, and basis set superposition error
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DOI：
10.1063/1.4755990
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发表时间：
2012-10-07
影响因子：
4.4
通讯作者：
Dannenberg, J. J.
中科院分区：
文献类型：
--
作者：
Roy, Dipankar;Marianski, Mateusz;Dannenberg, J. J.
我们使用包括CCSD(T)和MP2在内的从头算方法，比较了稀有气体二聚体以及Ne、甲烷和2-丁炔与HF和LiF的分散和诱导相互作用（包括一些专门用于评估分散相互作用的参数化函数）。我们看到，感应相互作用倾向于增强色散，并可能伴随着电荷转移。结果表明，在相互作用能量、基集叠加误差（BSSE）和相互作用距离作为基集大小的函数方面，泛函通常不遵循预期的趋势。与更高层次的计算相比，参数化处理色散相互作用的函数往往高估了这些相互作用，有时甚至高估了很多。哪种函数效果最好取决于所选择的示例。不描述纯粹色散相互作用的B3LYP和X3LYP泛函，似乎与那些参数化处理色散的泛函一样准确地描述了混合了感应的色散。我们观察到，在一个比许多数据库中用于生成结构的基集更大的基集中，高级波函数计算存在显著差异。我们讨论了基于这些数据库的高度参数化函数的含义，以及使用简单的势能来拟合参数，而不是考虑振动状态的实验确定的热力学状态函数。(C) 2012年美国物理研究所。[http://dx.doi.org/10.1063/1.4755990]
We compare dispersion and induction interactions for noble gas dimers and for Ne, methane, and 2-butyne with HF and LiF using a variety of functionals (including some specifically parameterized to evaluate dispersion interactions) with ab initio methods including CCSD(T) and MP2. We see that inductive interactions tend to enhance dispersion and may be accompanied by charge-transfer. We show that the functionals do not generally follow the expected trends in interaction energies, basis set superposition errors (BSSE), and interaction distances as a function of basis set size. The functionals parameterized to treat dispersion interactions often overestimate these interactions, sometimes by quite a lot, when compared to higher level calculations. Which functionals work best depends upon the examples chosen. The B3LYP and X3LYP functionals, which do not describe pure dispersion interactions, appear to describe dispersion mixed with induction about as accurately as those parametrized to treat dispersion. We observed significant differences in high-level wavefunction calculations in a basis set larger than those used to generate the structures in many of the databases. We discuss the implications for highly parameterized functionals based on these databases, as well as the use of simple potential energy for fitting the parameters rather than experimentally determinable thermodynamic state functions that involve consideration of vibrational states. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4755990]