使用第一原理计算了有序闪锌矿合金Si50Ge50的声子谱,与0GPa压力下的能带结构和直到20GPa压力的声子扩散曲线的压力依赖性.计算发现,在14GPa时,横向声学模式由压力导致软化,声子频率达到0,这表明对称性被打破,在高压下有新相生成。 Using the first principle, the phonon spectra of ordered sphalerite Si50Ge50 were calculated and the dependence of the pressure on the band structure at 0 GPa and the phonon diffusion curve up to 20 GPa was calculated. It was found that at 14 GPa, the transverse acoustic mode Softening by pressure causes the phonon frequency to reach zero, indicating that the symmetry is broken and new phase formation occurs at high pressure.