In this work, the structural and electronic properties of gallium phosphide (GaP) and (Si2)x(GaP)1-x solid solution were modeled using the density
functional theory (DFT). This method is an efficient and accurate method for calculating some parameters of semiconductor materials. The hybrid functional exchange-correlation Heyd-Scuceria-Ernzerhof (HSE) was used to correct the underestimation of the band gap. This work calculated and compared the lattice parameters and band gap of the GaP and (Si2)x(GaP)1-x solid solution with the experimental values.