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针对六角密堆金属锂16个原子超晶胞(supercell)、填隙一个氢原子的周期单元,采用基于密度泛函理论的平面波-赝势方法,研究了零温条件下压力及填隙氢掺杂对体系弹性性质的影响.结果表明氢掺杂导致体系的体模量增加.常压下掺杂体系的弹性常数C11,C33,C66和C12高于单质体系,剪切模量C44有所下降,而C13则与单质体系持平.压力作用下C11,C33和C66一直大于单质体系,但C12的值低于单质体系.在2GPa—4GPa压力区间内,弹性常数C13呈反常变化,小于单质体系;在高压区掺杂体系的C44和C13则高于单质体系的相应量值,压力导致掺杂体系和单质体系之间剪切模的偏离加剧.掺杂体系在压力作用下依然保持压缩模的各向同性,具有和单质体系相似的特性.
Aiming at the supercell of hexagonal close-packed metal lithium and the periodic unit of one hydrogen atom interstitial filling, the plane wave-pseudopotential method based on the density functional theory was used to study the effect of pressure and interstitial hydrogen doping The results show that hydrogen doping results in an increase in the bulk modulus of the system. The elastic constants C11, C33, C66 and C12 of the doped system are higher than those of the simple system at atmospheric pressure, and the shear modulus C44 is decreased , While C13 was the same as that of elemental system.C11, C33 and C66 were always larger than elemental system under pressure, but the value of C12 was lower than that of elemental system.In the pressure range of 2GPa-4GPa, the elastic constant C13 showed an abnormal change, C44 and C13 in the high-pressure zone doping system are higher than the corresponding values of the simple system, and the pressure causes the deviation of the shear mode between the doping system and the elemental system to be aggravated. The doping system still maintains the pressure of each To homosexuality, has the same characteristics and elemental system.