Cu-Ni bilayers either without defects (pristine) or with a single vacancy in the nickel layer at the interface (1-Ni-1), in the copper layer at the interface (1-Cu-1), in the central nickel layer (1-Ni-3), or in the central copper layer (1-Cu-3) were relaxed under the application of shear in the  direction. The DFT simulations were performed using Vienna Ab initio Simulation Package (VASP). The exchange-correlation potential was described by generalized gradient approximation (GGA) of Perdew-Burke-Ernzerhof (PBE) functional. The projected augmented wave method (PAW) and plane-wave basis set with an energy cutoff of 295.4 eV were used for all calculations, and they were conducted at the gamma point only. For energy minimization, the convergence criterion was set as 10^-4 eV.