LaNi_5-H体系计算机模拟  

Simulative calculations on LaNi_5-H

作　　者：桑革[1] 贾建平[1] 沈崇雨[1] 黄理[1] 陈长安[1] 武胜[1] 孙颖[1] 

机构地区：[1]中国工程物理研究院,绵阳621900

出　　处：《中国有色金属学报》2004年第F01期358-362,共5页The Chinese Journal of Nonferrous Metals

基　　金：中国工程物理研究院基金资助项目(20020865)

摘　　要：采用CASTEP软件,应用总能赝势方法对LaNi5与氢相互作用体系进行了模拟计算。计算中设置赝势为超软赝势,对交换关联能项采用广义梯度近似(GGA),对电子采用自旋极化处理。每个体系均采用完全的结构优化来计算平衡时的体系总能量。计算结果表明,氢原子在钯晶格中最有利位置是八面体间隙位,空位反而不利于氢原子占据。LaNi5H中氢原子在LaNi5晶格中最有利的位置是由2La2Ni组成的四面体间隙位。First-principles calculations on LaNi_5-H systems were made employing CASTEP software package. The ultrasoft pseudopotentials, generalized gradient approximation and electron spin polarized methods were used in calculations. A full geometry optimization was made to investigate the total energy of systems. From the calculated data it is found that the H atoms in vacancies are not stable although the volumes are bigger. H atoms are most prefer to diffuse in O-T-O pathway. The tetrahedral interstice consisting of 2La2Ni is the most stable site in perfect LaNi_5-H system. These two kinds of interfaces are all the most stable sites of H atoms. The H atoms will diffuse along the interface when trapped in it.

关 键 词：LaNi5-H体系 计算机模拟 总能赝势 氢 广义梯度近似 自旋极化 储氢材料 

分 类 号：TG139.7[一般工业技术—材料科学与工程] TP391.9[金属学及工艺—合金]