title: Excitation Spectra of Nucleobases with Multiconfigurational Density Functional Theory.
abstract: Range-separated hybrid methods between wave function theory and density functional theory (DFT) can provide high-accuracy results, while correcting some of the inherent flaws of both the underlying wave function theory and DFT. We here assess the accuracy for excitation energies of the nucleobases thymine, uracil, cytosine, and adenine, using a hybrid between complete active space self-consistent field (CASSCF) and DFT methods. The method is based on range separation, thereby avoiding all double-counting of electron correlation and is denoted long-range CASSCF short-range DFT (CAS-srDFT). Using a linear response extension of CAS-srDFT, we compare the first 7-8 excited states of the nucleobases with perturbative multireference approaches as well as coupled cluster based methods. Our results show that the CAS-srDFT method can provide accurate excitation energies in good correspondence with the computationally more expensive methods.
authors.affiliation: Department of Physics, Chemistry and Pharmacy, University of Southern Denmark , Campusvej 55, Odense M, Denmark.
authors.forename: Mickaël
authors.initials: M
authors.lastname: Hubert
authors.affiliation: Department of Physics, Chemistry and Pharmacy, University of Southern Denmark , Campusvej 55, Odense M, Denmark.
authors.forename: Hans Jørgen Aa
authors.initials: HJ
authors.lastname: Jensen
authors.affiliation: Laboratorium für Physikalische Chemie, ETH Zürich , Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland.
authors.forename: Erik D
authors.initials: ED
authors.lastname: Hedegård
mesh_terms: D008956:Models, Chemical; D009711:Nucleotides / Q000737:chemistry*
chemical_list: D009711:Nucleotides