title: Correlated four-component EPR g-tensors for doublet molecules.
abstract: The first correlated ab initio four-component calculations of electron paramagnetic resonance (EPR) g-tensors for doublet radicals are reported. We have implemented a first-order degenerate perturbation theory approach based on the four-component Dirac-Coulomb Hamiltonian and fully relativistic configuration interaction wave functions in the DIRAC program package. We find that the correlation effects on the g-tensors can be sufficiently well described with manageable basis sets of triple-zeta quality and manageable configuration spaces. The new fully relativistic EPR module in DIRAC should be useful for benchmarking density functional theory approaches, however, with future optimization of the code we believe it will also be useful for applications.
authors.affiliation: Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense M, Denmark.
authors.forename: Mads S
authors.initials: MS
authors.lastname: Vad
authors.forename: Morten N
authors.initials: MN
authors.lastname: Pedersen
authors.forename: Anette
authors.initials: A
authors.lastname: Nørager
authors.forename: Hans Jørgen Aa
authors.initials: HJ
authors.lastname: Jensen