Shining a light on amorphous U2O7: A computational approach to understanding amorphous uranium materials

Abstract Mixed-phase and low-symmetry systems are widely observed among uranium oxide materials. Amorphous-U 2 O 7 forms during the calcination of studtite, a uranyl peroxide mineral. Using a genetic algorithm search for stable crystalline phases, we have identified a potentially stable phase of U 2 O 7 that shares structural features with experimentally observed amorphous U 2 O 7 samples. The crystalline structure is expected to undergo a solid–solid phase change around 12 GPa.