Magnetic versus nonmagnetic polymorphs of RuBr3 under pressure

The delicate balance between magnetic and nonmagnetic states is central to the electronic properties of 4d and 5d honeycomb compounds, including prospective Kitaev materials. External pressure drives the recent Kitaev candidate α-RuBr₃ toward the magnetism collapse via structural dimerization, while at lower pressures this material evolves along the boundary between the ferromagnetic and zigzag orders. The alternative chain-like β polymorph is avoided despite its higher thermodynamic stability.