Chemical- and hydrostatic-pressure-controlled metallization in NiS2−xSex

External control parameters, including pressure, chemical substitution, and temperature, play a central role in modulating the electronic states of strongly correlated systems. In this study, we investigate the metal–insulator transition (MIT) in NiS _{2 −  x} Se _x under the combined influence of hydrostatic and chemical pressure. In pure NiS ₂ , the weak ferromagnetic transition temperature shifts in response to applied pressure. Metallization occurs at a relatively low pressure (1.3 kbar) for NiS _1.6 Se _0.4 , while lightly doped NiS _1.9 Se _0.1 requires higher pressure. At x  = 0.5, a metallic state arises solely from chemical substitution, without requiring external pressure. These results underscore the dominant influence of chemical pressure over hydrostatic compression and enable the construction of a unified pressure–doping–temperature phase diagram. These findings offer new insights into correlation-driven MITs and may inform the rational design of functional Mott systems.