Development of an interatomic potential for gallium antimonide and its application to structural, defect, and phase-stability properties

Abstract A classical interatomic potential for gallium antimonide (GaSb) was developed and thoroughly validated to reproduce its structural, mechanical, vibrational, and thermal properties. The model yields a lattice parameter, cohesive energy, bulk modulus, and elastic constants in close agreement with experimental measurements and density functional theory (DFT) results. The zinc-blende (ZB) phase is correctly stabilized, with a Ga–Sb bond length of 2.639 Å in excellent accordance with experiment. Defect energetics are well captured, with vacancy formation energies of E V Sb = 3.17 eV and E V Ga = 0.84 eV, reproducing the established DFT trend E V Sb > E V Ga . Surface energies for the (001) and (110) facets fall within the expected analytical range. The potential also predicts the transition from the ZB structure to the Imma phase near 11 GPa, consistent with experimental observations. The computed vibrational density of states reproduces the main experimental features, including the positions of the acoustic and optical peaks. Thermal behavior is likewise well represented, with the specific heat matching the experimental temperature dependence, a room-temperature thermal conductivity of 30 W m −1 K −1 , and a melting temperature of 1050 ± 50 K in good agreement with experiment.