An effective Hamiltonian in a basis of spin- and space-symmetry adapted configuration state functions (CSF), which includes information from Kohn–Sham density functional theory (DFT), is used to calculate configuration interaction (CI) wave functions for the electronic states of molecules. The method emphasizes on states of multiconfigurational character which cannot be represented by conventional DFT. The CI matrix elements are constructed empirically by using the exact operator and corrections from DFT. Both the optimized KS orbitals from the parent determinant and the corresponding KS potential from the parent state density are used. Depending on their energy gap the CI off-diagonal elements between CSF are exponentially scaled to zero to avoid double counting of electron correlation. The selection of the most important CSF describing nondynamical correlation effects and the use of an approximate resolution of the identity (RI) for the evaluation of the two-electron integrals allows a very efficient DFT/MRCI treatment of molecules with several hundreds of electrons. As applications, the prediction of excitation energies for singlet and triplet states of organic molecules and transition metal complexes, the calculation of electronic circular dichroism spectra and investigations of the energetics of diradicals are presented. It is found, that the new DFT/MRCI approach gives results of high accuracy (rms errors for relative energies <0.2 eV) comparable to those from sophisticated ab initio treatments.
Skip Nav Destination
,
Article navigation
1 October 1999
Research Article|
October 01 1999
A combination of Kohn–Sham density functional theory and multi-reference configuration interaction methods
Stefan Grimme;
Stefan Grimme
Institut für Physikalische und Theoretische Chemie, der Universität Bonn, Wegelerstraße 12, 53115 Bonn, Germany
Search for other works by this author on:
Mirko Waletzke
Mirko Waletzke
Institut für Physikalische und Theoretische Chemie, der Universität Bonn, Wegelerstraße 12, 53115 Bonn, Germany
Search for other works by this author on:
Stefan Grimme
Mirko Waletzke
Institut für Physikalische und Theoretische Chemie, der Universität Bonn, Wegelerstraße 12, 53115 Bonn, Germany
J. Chem. Phys. 111, 5645–5655 (1999)
Article history
Received:
May 27 1999
Accepted:
July 09 1999
Citation
Stefan Grimme, Mirko Waletzke; A combination of Kohn–Sham density functional theory and multi-reference configuration interaction methods. J. Chem. Phys. 1 October 1999; 111 (13): 5645–5655. https://doi.org/10.1063/1.479866
Download citation file:
Pay-Per-View Access
$40.00
Sign In
You could not be signed in. Please check your credentials and make sure you have an active account and try again.
Citing articles via
DeePMD-kit v2: A software package for deep potential models
Jinzhe Zeng, Duo Zhang, et al.
CREST—A program for the exploration of low-energy molecular chemical space
Philipp Pracht, Stefan Grimme, et al.