Design and Parameterization of a DFT/MRCI Hamiltonian for Radicals with Odd Numbers of Electrons

• Applicant: Professorin Dr. Christel M. Marian
• Subject Area: Theoretical Chemistry: Electronic Structure, Dynamics, Simulation ; Theoretical Chemistry: Molecules, Materials, Surfaces
• Term: from 2013 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 245515727

The primary goal of this project is to develop a cost-efficient electronic structure method that is capable of describing electronically excited states of various types (pi-pi, n-pi, Rydberg states, double excitations, charge-transfer states, ...) and spin multiplicities in a balanced manner. In the first funding period, the Hamiltonian of the combined density functional theory / multi-reference configuration interaction (DFT/MRCI) method was redesigned und reparameterized for even numbers of electrons and was shown to produce qualitatively correct results also for excimers and bi-chromophoric systems where the original DFT/MRCI Hamiltonian fails. In the second funding period, we aim at a consistent extension of our ansatz to systems with an odd number of electrons using a spinrestricted formalism. This method extension will allow to compute electronic spectra of doublet and quartet molecules as well as oxidation and ionization processes of singlet and triplet molecules at the same footing. On the application side, we set out for a comprehensive theoretical study of the electronic structure of large persistent neutral radicals that could build the basis for a new type of organic light-emitting diode emitters.

• DFG Programme: Research Grants