The main goal of this project is to develop and employ an efficient protocol to compute electronic and vibrational properties of 3D and 2D optoelectronic materials. Our investigation group at Uppsala Universality (PI: Tomas Edvinsson) has received financial support from the Swedish Energy Agency for fundamental research (Proj id: P2020-90215, until 2026) and the Swedish Research Council, VR (Proj id. 2023-05244, until 2027). The project goal is to investigate electronic and vibrational effects in 3D/2D materials and the dependence on low dimensionality and inclusion for heavy elements for metal halide perovskites. Here, method beyond standard density functional theory is needed where computational demanding GW, Bethe-Salpeter, and linear response approaches for 2D crystals are necessary to describe the excitonic behaviour of the 2D materials and their coupling to the lattice. Transition metal dichalcogenides will also be investigated.