Theoretical Chemistry

This project focuses on the development and application of ab initio quantum chemical models for the description of localized electronic excitations in solids, using the embedded cluster model as a main vehicle to model materials. Special attention is given to the electronic structure of transition metal compounds. New embedding techniques are being developed and explored. With the embedded cluster approach local electron correlation effects, as well as relaxation effects can be efficiently treated.

we use wavefunction based methods and more specifically CASSCF/PT2 (a complete active space self consistent field method, extended wtih second order perturbation theory). This method has proven to be able to give accurate descriptions of the complicated electronic structure of transition metals compounds, which is not easily described with other ab initio quantum chemical approaches. A powerful feature of our ab initio quantum chemical approach is that reliable calculations of the various properties can be combined with careful analysis of the wavefunctions to determine the physical and chemical origin of these properties.

In the past years research interest in this project has focused on ground and excited state properties of transition metal impurities in semiconductors and alkalihalogenides as well as of first row transition metal oxides and halogenides. The factors that govern the magnetic interactions in for example NiO and its surfaces have also been studied.