Elastic Properties of Potassium Halides under Pressure

钾卤化物 KX 的中等压力的有弹性的性质(X=F， Cl， Br ) 用密度理论上被学习有标准保存的功能的理论(DFT ) 假潜力方法。到更稠密的 B2 阶段(CsCl类型结构)的从 B1 阶段(NaCl类型结构)的阶段转变为 KF ， KCl 和 KBr 发生在 7.7,3.46 和 2.96 GPa ，这些材料的 respectively.The 橡皮僵硬系数和体积模数作为静水力学的压力并且与两个相比的功能被计算试验性、理论的价值。

The moderate-pressure elastic properties of potassium halides KX （X=F, Cl, Br） was studied theoretically using the density functional theory （DFT） with normconserving pseudopotentials method. The phase transformation from the B1 phase （NaCl-type structure） to the denser B2 phase （CsCl-type structure） occurred at 7.7, 3.46 and 2.96 GPa for KF, KCI and KBr, respectively. The elastic stiffness coefficients and bulk modulus of these materials were calculated as function of hydrostatic pressure and compared with both the experimental and theoretical values.