LaNi4.75Al0.25储氢材料的密度泛函理论研究

The Density Functional Theory Study for LaNi4.75Al0.25 Hydrogen Storage Materials

摘要:

在全电子水平上，基于广义梯度近似（GGA）密度泛函和全势能线性缀加平面波方法（FLAPW），研究了LaNi4.75Al0.25的晶体结构。采用GGA Perdew96交换相关泛函，计算给出了LaNi4.75Al0.25的晶胞参数为a=b=0．5033nm、c=0．4018nm、a／c=1．252，Al原子最可能占据的3g格位的等效位置（0．75，0，0．5），计算还给出了合金的能带结构、态密度（DOS）和电荷密度图，计算结果与实验值符合得相当好。

Abstract:

The geometrical and electronic structures for LaNi4.75Al0.25 compound have been calculated with the generalized gradient approximation(GGA)Pewdew96 of density functional and the Full-potential linearized augmented plane wave(FLAPW)method.The results indicate that the optimized cell parameters are a=b=0.5033 nm,c=0.4018 nm and a/c=1.252,and Al atom is most likely to occupy the(0.75,0.0,0.5)position in the super-cell-the equivalent position of 3g of LaNi5 mono-cell.The band structure,density of states(DOS)and charge densities for this compound are also worked out.All the theoretical results are in well agreement with the experimental data.