Theoretical development for excited states

At critical geometries such as conical intersections—where Time-Dependent Density Functional Theory (TD-DFT) often fails—the MSM-DFT diagrammatic approach, developed through in-depth Many-Body Perturbation Theory (MBPT) analysis, is a very promising alternative to obtain a more accurate description of the ground state curve. We want to improve this methodology to obtain a TD-MDET-DFT