Background
The current state-of-the-art ab-initio computations on solids are essentially always based on the so-called Born-Oppenheimer (BO) approximation. There are some rare, but interesting cases, where the BO approximation may fail and we may have to go beyond it for accurate results. Conventional methods, like the original wave function approach, is not computationally feasible in solids as it has poor scaling as a function of system size.
With these points in mind, we have developed reformulations of the Coulombic many-body quantum mechanical problem by using field theoretic approaches that are valid beyond the BO approximation. These approaches are more feasible from the computational point of view than the wave function approach and allows the computation of any observable.
Goals
Development of more sophisticated theoretical tools to describe in more detail systems like molecules and solids.
Implementation of the developed theoretical tools to study realistic systems by computations.
With the theoretical and computational tools developed, to gain understanding of relevant phenomena of interest.