通过高水平CCSDT（Q）复合从头算方法重新检查原型pi-pi二聚体
Prototypical pi-pi dimers re-examined by means of high-level CCSDT(Q) composite ab inito methods
摘要：
苯乙烯和平行置换（PD）苯。苯二聚体是涉及p-p堆积相互作用的最基本的体系。一些高水平的从头算研究在CCSD（T）/CBS理论水平上使用各种方法计算了这些二聚体的结合能，例如约化虚拟轨道空间和/或基于MP2的基组校正。在这里，我们使用Weizmann-3型方法获得CCSDT（Q）结合能。特别地，我们使用大的重原子增广高斯基组（即SCF/jul-cc-pV{5，6}Z，CCSD/jul-cc-pV{Q，5}Z和（T）/jul-cc-pV{T，Q}Z）外推SCF，CCSD和（T）分量。我们考虑后CCSD（T）的贡献CCSDT（Q），内壳，标量相对论，和玻恩-奥本海默修正。总的来说，我们最好的相对论，全电子CCSDT（Q）结合能是Δ Ee，all，rel = 1.234（苯...乙烯）和2.550（苯...苯PD），Δ H_0 = 0.949（苯PD），Δ H_0 = 0.949（苯PD），Δ H_0 = 0.949（苯PD）。乙烯）和2.310（苯...苯PD）和Δ H298 = 0.130（苯...乙烯）和1.461（苯...苯PD）kcal/mol。关于SCF、CCSD、（T）和post-CCSD（T）分量的基组收敛性，得到了重要的结论。解释相关的计算被用来作为常规的结合能的合理性检查。总的来说，CCSD（T）后的贡献是不稳定的0.028（苯...乙烯）和0.058（苯）。苯）kcal/mol，因此，如果寻求0.1 kcal/mol的准确度，则不能忽略它们。
英文摘要：
The benzene...ethene and parallel-displaced (PD) benzene...benzene dimers are the most fundamental systems involving p-p stacking interactions. Several high-level ab initio investigations calculated the binding energies of these dimers at the CCSD(T)/CBS level of theory using various approaches such as reduced virtual orbital spaces and/or MP2-based basis set corrections. Here we obtain CCSDT(Q) binding energies using a Weizmann-3-type approach. In particular, we extrapolate the SCF, CCSD, and (T) components using large heavy-atom augmented Gaussian basis sets (namely, SCF/jul-cc-pV{5,6}Z, CCSD/jul-cc-pV{Q,5}Z, and (T)/jul-cc-pV{T,Q}Z). We consider post-CCSD(T) contributions up to CCSDT(Q), inner-shell, scalar-relativistic, and Born-Oppenheimer corrections. Overall, our best relativistic, all-electron CCSDT(Q) binding energies are Delta Ee,all,rel = 1.234 (benzene...ethene) and 2.550 (benzene...benzene PD), Delta H0 = 0.949 (benzene...ethene) and 2.310 (benzene...benzene PD), and Delta H298 = 0.130 (benzene...ethene) and 1.461 (benzene...benzene PD) kcal/mol. Important conclusions are reached regarding the basis set convergence of the SCF, CCSD, (T), and post-CCSD(T) components. Explicitly correlated calculations are used as a sanity check on the conventional binding energies. Overall, post-CCSD(T) contributions are destabilizing by 0.028 (benzene...ethene) and 0.058(benzene...benzene) kcal/mol, thus they cannot be neglected if 0.1 kcal/mol accuracy is sought.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
