Mickael Delcey

Mickael Delcey is a researcher at  the Department of Theoretical Chemistry and Biology at KTH Royal Institute of Technology, Stockholm, Sweden.

Development of multiconfigurational methods

His main focus is the development of quantum chemical methods able to accurately describe systems with strong (also called static) correlation. These are cases for which the intuitive concept of molecular orbital breaks down, and thus a single Slater determinant does not give an even qualitatively reasonable picture of the electronic structure.

Most of quantum chemistry has evolved to describe molecules where a single Slater determinant is a good starting point and can break down, sometimes spectacularly, for more complex systems. Multiconfigurational methods are the natural generalisation of standard quantum chemistry methods to strong correlation problems, and his goal is to bring these methods to the same level of sophistication as the rest of quantum chemistry. The ambition is that researchers would not fear switching to a multiconfigurational method when they think the system they are studying may require it.

In particular, he is currently interested in hybrid DFT and MCSCF schemes, as well as new and more efficient formulation of perturbation theory on top of a MCSCF wavefunction. Methods to replace the expensive configuration interaction treatment within the active space are also an important focus. Finally, he is working on the implementation of efficient linear response equations to compute absorption and emission spectra, both at the UV-visible and X-ray energy ranges.

Transition metal spectroscopy and homogeneous catalysis

Catalysis lies at the core of chemistry, and transition metals are often key elements. Mickael's interests are in particular red-ox catalysist with multiple transition metals, both in biological (hydrogenase, oxygen-evolving complex and nitrogenase for example) and in synthetic systems. His current focus is the simulation of X-ray absorption spectra of these systems and especially how the coupling between the two (or more) metals affect the spectral signatures.