Researchers at Henan University, Yanshan University, Minzu University of China, and Riphah International University have used first-principles calculations to investigate how oxygen and water interact with the surface of Cs 2 SnI 6 , a lead-free, vacancy-ordered double perovskite being explored as an alternative to lead-halide perovskites in solar cells. Using dispersion-corrected density functional theory (DFT-D3), the team examined molecular and dissociative adsorption of O 2 and H 2 O across