## Abstract

Using explicitly-correlated coupled-cluster theory with single and double excitations, the intermolecular distances and interaction energies of the T-shaped imidazole⋯benzene and pyrrole⋯benzene complexes have been computed in a large augmented correlation-consistent quadruple-zeta basis set, adding also corrections for connected triple excitations and remaining basis-set-superposition errors. The results of these computations are used to assess other methods such as Møller-Plesset perturbation theory (MP2), spin-component-scaled MP2 theory, dispersion-weighted MP2 theory, interference-corrected explicitly-correlated MP2 theory, dispersion-corrected double-hybrid density-functional theory (DFT), DFT-based symmetry-adapted perturbation theory, the random-phase approximation, explicitly-correlated ring-coupled-cluster-doubles theory, and double-hybrid DFT with a correlation energy computed in the random-phase approximation.

Original language | English (US) |
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Pages (from-to) | 17-22 |

Number of pages | 6 |

Journal | Chemical Physics |

Volume | 441 |

DOIs | |

State | Published - Sep 30 2014 |

### Bibliographical note

Funding Information:K.D.V. and W.K. gratefully acknowledge support by the DFG through the Center for Functional Nanostructures (CFN, Grant No. C3.3). A.S.H. gratefully acknowledges support by the Fonds der Chemischen Industrie (FCI) through a Chemiefonds Fellowship.

## Keywords

- Basis-set limit
- Coupled-cluster theory
- Double-hybrid density functionals
- Explicitly-correlated wavefunctions
- Noncovalent interactions
- Random-phase approximation