(中國工程物理研究院, 綿陽 621900)
摘 要: 采用CASTEP軟件,應用總能贗勢方法對LaNi5與氫相互作用體系進行了模擬計算。計算中設(shè)置贗勢為超軟贗勢, 對交換關(guān)聯(lián)能項采用廣義梯度近似(GGA),對電子采用自旋極化處理。 每個體系均采用完全的結(jié)構(gòu)優(yōu)化來計算平衡時的體系總能量。 計算結(jié)果表明, 氫原子在鈀晶格中最有利位置是八面體間隙位, 空位反而不利于氫原子占據(jù)。 LaNi5H中氫原子在LaNi5晶格中最有利的位置是由2La2Ni組成的四面體間隙位。
關(guān)鍵字: LaNi5; 氫; 模擬
(China Academy of Engineering and Physics,
Mianyang 621900, China)
Abstract:First-principles calculations on LaNi5-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 LaNi5-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.
Key words: LaNi5; hydrogen; simulation


