# The dispersion interaction between quantum mechanics and effective fragment potential molecules

Title | The dispersion interaction between quantum mechanics and effective fragment potential molecules |

Publication Type | Journal Article |

Year of Publication | 2012 |

Authors | Smith QA, Ruedenberg K, Gordon MS, Slipchenko LV |

Journal Title | Journal of Chemical Physics |

Volume | 136 |

Pages | 244107 |

Date Published | 06 |

Type of Article | Article |

ISBN Number | 0021-9606 |

Accession Number | WOS:000305881100009 |

Keywords | atom-atom potentials, BASIS-SETS, BENCHMARK CALCULATIONS, BENZENE DIMER, damping, density-functional theory, energy, functions, intermolecular potentials, orbital methods, wave-functions |

Abstract | A method for calculating the dispersion energy between molecules modeled with the general effective fragment potential (EFP2) method and those modeled using a full quantum mechanics (QM) method, e. g., Hartree-Fock (HF) or second-order perturbation theory, is presented. C-6 dispersion coefficients are calculated for pairs of orbitals using dynamic polarizabilities from the EFP2 portion, and dipole integrals and orbital energies from the QM portion of the system. Dividing by the sixth power of the distance between localized molecular orbital centroids yields the first term in the commonly employed London series expansion. A C-8 term is estimated from the C-6 term to achieve closer agreement with symmetry adapted perturbation theory values. Two damping functions for the dispersion energy are evaluated. By using terms that are already computed during an ordinary HF or EFP2 calculation, the new method enables accurate and extremely rapid evaluation of the dispersion interaction between EFP2 and QM molecules. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4729535] |

URL | <Go to ISI>://WOS:000305881100009 |

DOI | 10.1063/1.4729535 |

Alternate Journal | J. Chem. Phys. |