In this paper, based on density functional theory, the structural stability and mechanical properties of AuIn2 doped with RE (RE = Y, Sc) were investigated. The bulk modulus, shear modulus, Young’s modulus and Poisson’s ratio of the materials were calculated by Viogt−Reuss−Hill approximation. The calculation results show that Sc−SAu (trace of Au substituted by Sc in AuIn2), Y−SAu and Y−SIn have stable structure, and Y−SAu has obvious effect on the toughness indexes of AuIn2 alloy. Furthermore, based on Clarke and Cahill modes, the lattice thermal conductivity of the intermetallic compound was calculated and shows the same tendency with the Debye temperature and fast heat transfer rate in the direction of [110].
