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

该项目的主要目标是开发一种具有成本效益的电子结构方法，能够以平衡的方式描述各种类型的电子激发态（pi-pi, n-pi，里德堡态，双重激发，电荷转移态等）和自旋多重性。在第一个资助阶段，对密度泛函理论/多参考构型相互作用（DFT/MRCI）方法的哈密顿量进行了重新设计并重新参数化，结果表明，在原始DFT/MRCI哈密顿量失效的准分子和双显色体系中，哈密顿量也产生了定性正确的结果。在第二个资助期，我们的目标是使用自旋限制形式主义将我们的分析一致地扩展到具有奇数电子的系统。这种方法的扩展将允许计算双重态和四重态分子的电子谱，以及单重态和三重态分子的氧化和电离过程。在应用方面，我们着手对大型持久性中性自由基的电子结构进行了全面的理论研究，为新型有机发光二极管的发射奠定了基础。

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.