Final Report Summary - NEWQUANTUM (Development of multi-level electron correlation methods in quantum chemistry)
In the beginning of the project I set out to improve the application range of quantum chemistry methods using multi-level techniques. During the last three years, I have together with my collaborators succeeded in developing several new approaches and they appear very promising. These developments have focused on Hartree-Fock and coupled cluster theories, with emphasis on response properties.
Shortly after arriving at Stanford University, the first period of the project, I got involved in a collaboration with the experimental group lead by Prof. Markus Gühr, on the excited state dynamics of thymine. This collaboration has spurred many development project in coupled cluster theory for X-ray phenomena. The results of the collaboration has been published in Nature Communications and SLAC published in this connection the following press release: https://www6.slac.stanford.edu/news/2017-06-22-single-electrons-tiny-leap-sets-molecular-sunscreen-response.aspx
During the thymine collaboration, we encountered some very fascinating conical intersections. A notorious case in coupled cluster theory is the inability to describe these phenomena. During the second period of the project at NTNU, we have made a concerted effort to resolve this long-standing problem. I'm please that we now have resolved the problem and can submit our findings for publication.