The pressure-dependent physical properties of the half-Heusler alloy HfNiSn were investigated via first-principles calculations within the PBE-GGA framework. Structural optimization revealed that HfNiSn is most stable in a nonmagnetic γ-phase cubic structure (space group F \(\overline{4}3m\) ). Electronic structure analysis revealed semiconducting behavior with an indirect band gap of 0.36 eV, whereas the formation and cohesive energy values confirmed its thermodynamic stability. The calculated elastic constants, Young’s moduli, shear moduli, and Poisson’s ratios demonstrate the mechanical stability and ductility characteristics for the studied pressure range. The optical spectra indicate strong absorption in the visible and ultraviolet regions, with the optical conductivity being maximized in the visible range and enhanced under pressure. These findings highlight the favourable electronic, mechanical, and optical properties of HfNiSn, supporting its potential in future optoelectronic applications.
