6X6?C2X n π–π complexes?]]>

摘要

Graphical abstract Display Omitted Highlights ? Determines CCSD(T)/CBS binding energies for C6X6?C2X n complexes. ? The complexation energies range between 11.1 and 34.0kJmol? 1. ? Evaluates the performance of a wide range of DFT and ab initio methods. ? The G4 and G4(MP2) methods exhibit surprisingly poor performance. ? Identifies the best performing DFT and double-hybrid DFT functionals. Abstract We calculate the CCSD(T)/CBS complexation energies of C6X6?C2X n complexes (X=F, Cl; n =2, 4) by means of the W1-F12 and CCSD(T)/MP2(CBS) procedures. These complexes involve π–π stacking, charge-transfer, and van der Waals interactions and their complexation energies range between 11.1 (C6F6?C2F2) and 34.0 (C6Cl6?C2Cl4)kJmol? 1. We use our best CCSD(T)/CBS data to assess the performance of DFT, double-hybrid DFT (DHDFT), and standard/composite ab initio methods. The G4 and G4(MP2) composite methods show relatively poor performance with root-mean-square deviations (RMSDs) of 8.7 and 6.3展开▼