joint CASUS Institute Seminar, Prof. Lucia Reining, Senior Scientist and Matteo Gatti, PhD, Centre National de la Recherche Scientifique (CNRS), Paris

Prof. Lucia Reining holds a PhD in physics. After a Marie Curie postdoctoral fellowship at the Centre Européen de Calcul Atomique et Moléculaire in Orsay, she became a research associate at CNRS. Lucia was appointed Research Director (Special Class) at the French National Center for Scientific Research (CNRS) in the Laboratoire des Solides Irradiés at École Polytechnique in 2016.

Dr. Matteo Gatti holds a PhD in physics. He is a permanent researcher at LSI – CNRS Ecole Polytechnique in the Theoretical Spectroscopy group.

Abstract of the talk // The use of functionals of compact quantities, such as Green’s functions, the one-body reduced density matrix, or the density, is a powerful alternative to wavefunction-based methods. In this talk, Lucia and Matteo will start from general strategies that are common to different approaches relying on functionals, briefly discussing ideas and major concepts. Both will investigate the difficulties of finding good approximations, and highlight some strategies for improvement that allow us to consider Density Functional Theory, Many-Body Perturbation Theory, and Dynamical Mean Field Theory on the same footing.

In particular, Lucia and Matteo will concentrate on the way in which models make such first principles electronic structure calculations feasible. This relies on powerful methods, including wavefunction-based ones, to provide benchmarks (1), and to solve the models. One of the most prominent models is the homogeneous electron gas, whose spectroscopic properties still have to be explored. This point will be illustrated by discussing the low-density regime (2). Lucia and Matteo will then propose a well defined and systematic way for a utilization of models, which they termed connector theory (3,4), and which can be used to design new classes of functionals. Illustrations for progress and remaining difficulties will conclude the seminar.

1.       A. Aouina, M. Gatti, S. Chen, S. Zhang, and L. Reining

2.       J. Koskelo, L. Reining and M. Gatti

3.       M. Vanzini, A. Aouina, M. Panholzer, M. Gatti, and L. Reining, npj Comput Mater 2022, 8, 98

4.       A. Aouina, M. Gatti, and L. Reining,  Faraday Discussions 2020, 224, 27

The seminar will be held exclusively online via Zoom Inc., people interested in the topic have the chance to also join the talk remotely. Please ask for the login details via