Skip to Main content Skip to Navigation
Journal articles

Ensemble density functional theory method correctly describes bond dissociation, excited state electron transfer, and double excitations

Abstract : State-averaged (SA) variants of the spin-restricted ensemble-referenced Kohn-Sham (REKS) method, SA-REKS and state-interaction (SI)-SA-REKS, implement ensemble density functional theory for variationally obtaining excitation energies of molecular systems. In this work, the currently existing version of the SA-REKS method, which included only one excited state into the ensemble averaging, is extended by adding more excited states to the averaged energy functional. A general strategy for extension of the REKS-type methods to larger ensembles of ground and excited states is outlined and implemented in extended versions of the SA-REKS and SI-SA-REKS methods. The newly developed methods are tested in the calculation of several excited states of ground-state multi-reference systems, such as dissociating hydrogen molecule, and excited states of donor-acceptor molecular systems. For hydrogen molecule, the new method correctly reproduces the distance dependence of the lowest excited state energies and describes an avoided crossing between the doubly excited and singly excited states. For bithiophene-perylenediimide stacked complex, the SI-SA-REKS method correctly describes crossing between the locally excited state and the charge transfer excited state and yields vertical excitation energies in good agreement with the ab initio wavefunction methods. (C) 2015 AIP Publishing LLC.
Document type :
Journal articles
Complete list of metadatas

https://hal-amu.archives-ouvertes.fr/hal-01415154
Contributor : Didier Siri <>
Submitted on : Monday, December 12, 2016 - 6:49:09 PM
Last modification on : Thursday, December 5, 2019 - 10:40:03 AM

Identifiers

Collections

Citation

Michael Filatov, Miquel Huix-Rotllant, Irene Burghardt. Ensemble density functional theory method correctly describes bond dissociation, excited state electron transfer, and double excitations. Journal of Chemical Physics, American Institute of Physics, 2015, 142 (18), pp.184104. ⟨10.1063/1.4919773⟩. ⟨hal-01415154⟩

Share

Metrics

Record views

109