First principles method based on density functional theory is performed to firstly calculate structural, elastic and thermodynamic properties of CrSi, TiSi and ZrSi under high pressure. Calculated structural parameters are excellently constant with previous experimental and theoretical results and decrease with variation pressures. All phonon dispersion curves have no imaginary frequency and elastic constants fulfil Born’s criteria admirably indicating that all of them are dynamically and mechanically stable. Elastic constants C_ij increase linearly with pressure. Calculated bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio and B/G increase linearly with increasing pressures, which reveals that the material hardness can be improved by raising external pressure. In addition, external pressure can also improve the ductility of materials, which makes them as promising candidates for malleable metal alloy in industrial application. Debye temperature increases with increasing pressures, while heat capacity reduces slightly with increasing pressures. In the end, we did a detailed analysis of the heat capacity under variation of temperature and pressure.

运用基于密度泛函理论的第一性原理方法，首先计算了高压下CrSi，TiSi和ZrSi的结构，弹性和热力学性质。计算得到的结构参数与先前的实验和理论结果具有极好的常数，并且随着压力的变化而减小。所有的声子色散曲线都没有假想的频率，并且弹性常数满足Born准则，令人钦佩地表明它们全部都是动态和机械稳定的。弹性常数C _ij随压力线性增加。计算的体积模量，剪切模量，杨氏模量，泊松比和B / G随着压力的增加线性增加，这表明可以通过增加外部压力来提高材料硬度。此外，外部压力还可以改善材料的延展性，使其成为工业应用中可锻金属合金的有希望的候选者。德拜温度随压力增加而增加，而热容随压力增加而略有下降。最后，我们对温度和压力变化下的热容量进行了详细分析。