高压下单晶LiF的光学及热力学性质的密度泛函理论研究

Ab initio simulations of optical and thermodynamic properties of LiF

采用平面波赝势密度泛函方法，对单晶氟化锂（LiF）在0-500GPa静水压下的光学性质进行了理论研究。并利用Vinet状态方程和准简谐Debye模型得到了其热力学性质．理论计算结果表明单晶氟化锂（LiF）在0-500GPa静水压范围内具有良好的透明性。吸收波段随压强的增加而出现了蓝移．计算所得晶格常数、体积模量度其对压强的一阶导数与实验值相符合．

The optical properties of single crystal Lithium Fluoride （LiF） are investigated by means of a planewave pseudopotential density functional theory method in a range of hydrostatic pressure up to 500 GPa. The calculation results show a blue shift at absorption wavelength with the pressure increasing. The absorption spectrums suggest that Lithium Fluoride （LiF） keep a good transparent when used as the window materials in shock temperature measuring. The thermodynamies properties are obtained through Vinet equation of state and quasi-harmonic Debye model. The calculated lattices constant, bulk modulus and pressure its first derivative are in good agreement with the experimental data.