The structural, elastic and thermal properties of MgGeP2 crystal have been studied comprehensively with the first-principle based on the density function theory. The equilibrium lattice constant, the energy gap, the elastic coefficient and other related thermal parameters of MgGeP2 have been discussed in this paper. The results are analyzed theoretically and show that the compound of MgGeP2 at zero-pressure is direct band-gap semiconductor and the value of energy gap is 1.522eV. Furthermore, Calculation of elastic properties in this crystal indicates the MgGeP2 is an anisotropic and ductile material. In addition, the effect of temperature and pressure thermal properties such as Debye temperature, the thermal expansion coefficient, the heat capacity Cv and Cp are also worked out by the quasi-harmonic Debye model in the rang of 0~40GPa and 0~800K.
