This project aims at studying solid solutions containing several transition metals. Solid solutions are fundamental to modern energy generation and storage. These materials consist of a homogeneous mixture of multiple metals in solid state sharing a single crystal structure. These materials are characterized by intricate atomic local configurations, variable oxidation states, and a lack of short-range order. This complexity makes difficult to correlate their atomic structure with their physicochemical properties. Theoretical computations using Density Functional Theory (DFT) can provide an insight into the electronic properties of these complex solid solutions. We will investigate the effects of atomic clustering on their formation energies and electronic properties. Catalytic activities will be investigated using a descriptor-based approach adapted for heterogeneous surfaces. Crystal lattices will be prepared based on experimental information and populated by randomly assigning cations to different sites in the lattice.