In recent years we have had a strong interest toward the development of methods for calculating higher-order molecular properties and vibrational contributions to these properties. The present proposal will seek to extend this work from scattering process es to absorption processes, and in particular to the study of vibronic effects on higher-order molecular properties.The work will be carried in close collaboration with the group of Prof.Marcel Nooijen at the University of Waterloo (Canada).
In one part of the project we will continue to develop and extend various approximations to the vibronic problem. This will in part include the development of new algorithms for solving the full vibrational problem, with the aim of increasing the size of the molecula r systems that can be handled, as well as develop faster algorithms for more approximate vibronic models, such as the Franck-Condon approximation. These developments will be made in the IBRON program system developed during the last 5 years in the researc h group of Prof.Nooijen, and the postdoc hired is expected to spend up to two years in this group before bringing the technology to Norway with a final year in the group of Prof.Ruud.
The second part of the project will be devoted to establishing the nec essary diabatization scheme in the Dalton quantum chemistry program in order to allow for the evaluation of the many properties accessible in Dalton. We also intend to extend Dalton to new higher-order properties for which vibronic effects are expected to be important, such as Magneyic Circular Dichroism (MCD) and resonance Raman and resonance Raman optical activity. If time allows, vibronic contributions to technologically important processes such as two-photon absorption may also be considered.