第一原理研究氢化钾的相变和弹性(英文)

Phase Transition and Elastic Properties of KH Via First-principles Calculations

利用密度泛函的赝势平面波理论研究了KH的B1到B2相变和弹性.发现在4.02 GPa时,KH由B1相转变为B2相,同时获得了不同压力下弹性常数cij、体变模量BS和剪切模量G以及德拜温度ΘD.结果表明,随着压力增长弹性常数的变化与相变关系更为密切.

The structural B1-B2 phase transition of KH and the elastic properties of the B1 and B2 phases of KH are investigated by using the pseudopotential plane-wave within density functional theory method. From the u- sual condition of equal enthalpies, we find that the structure B1-B2 phase transition of KH occurs at 4.02 GPa. The dependences of the elastic constants co, the aggregate elastic modulus Bs and G, and the Debye temperature/9D on pressure are successfully obtained. The calculated results suggest that with increasing pressure the predicted elastic constants are closely related to the pressure-induced structural phase transition from B1 to B2.