Laboratoire CEISAM - UMR CNR 6230, Université de Nantes, 2 Rue de la Houssinière, BP 92208, 44322 Nantes Cedex 3, France, and Ecole Nationale Supérieure de Chimie de Paris, Laboratoire Electrochimie et Chimie Analytique, UMR CNRS-ENSCP no. 7575, 11, rue Pierre et Marie Curie, F-75321 Paris Cedex 05, France.
J Chem Theory Comput. 2011 Feb 8;7(2):369-76. doi: 10.1021/ct1006532. Epub 2010 Dec 29.
We have computed the bond length alternation (BLA) in a series of π-conjugated quasilinear chains containing from two to six unit cells. Several structures (eight oligomeric sets including three conformers of polyacetylene, polymethineimine, polysilaacetylene, etc.) have been considered to cover the possible evolutions of the BLA with increasing chain length. Three objectives have been tackled: (1) the computation of accurate reference values using the CCSD(T) theory; (2) an evaluation of the performances of other electron correlated wave function approaches (MPn, SCS-MP2, CCSD, etc.); (3) the benchmarking of several DFT functionals, including global, range-separated, and double hybrids. It turns out that the SCS-MP2 approach is, on average, an efficient scheme in terms of its accuracy/cost ratio. Among the selected DFT approaches, no single functional emerges as uniformly accurate for all oligomeric series and chain lengths, but BHHLYP, M06-2X, and CAM-B3LYP could be reasonable choices for long oligomers.
我们计算了一系列含有两到六个单元的准线性共轭π键中的键长交替（BLA）。为了涵盖 BLA 随链长增加的可能演变，我们考虑了几种结构（包括聚乙炔、聚亚甲胺、聚硅亚乙炔等的 8 个低聚物组，共 3 种构象）。我们解决了三个目标：（1）使用 CCSD(T)理论计算准确的参考值；（2）评估其他电子相关波函数方法（MPn、SCS-MP2、CCSD 等）的性能；（3）基准测试几种 DFT 泛函，包括全局、区间分离和双杂交。结果表明，SCS-MP2 方法在准确性/成本比方面平均来说是一种有效的方案。在所选择的 DFT 方法中，没有一个单一的泛函对于所有低聚物系列和链长都具有统一的准确性，但 BHHLYP、M06-2X 和 CAM-B3LYP 可能是长低聚物的合理选择。
