(廣西大學 物理科學與工程技術學院，教育部有色金屬材料及其加工新技術重點實驗室，南寧 530004)
摘 要: 采用基于密度泛函理論(DFT)的平面波贗勢(PW-PP)方法，計算Li-Al-N-H系絡合物貯氫反應中各個化合物的晶胞參數(shù)、電子結構、生成焓和貯氫反應的反應焓。結果表明：Li3AlN2的Li—N、Al—N鍵主要為離子鍵，LiNH2的N—H鍵主要為共價鍵，Li—N鍵主要為離子鍵；298 K時貯氫反應的反應焓計算值分別為−23.7和−55.3 kJ/mol，與實驗值均符合得較好；反應中各固態(tài)、氣態(tài)物質(zhì)的晶胞的結構優(yōu)化后的晶格常數(shù)、鍵長與鍵角等與相應的實驗值均符合較好。
關鍵字: Li-Al-N-H絡合物；電子結構；反應焓；第一性原理
hydrogen storage by first principle
（Key Laboratory of National Education Ministry for Nonferrous Metals and Materials Processing Technology,
College of Physical Science and Technology, Guangxi University, Nanning 530004, China）
Abstract:The cell parameters, electronic structures, formation enthalpies and reaction enthalpies of LiNH2 and Li3AlN2 were investigated using plane-wave pseudo-potential method based on density function theory. The results show that the calculated cell parameters are in agreement with the experimental ones. The interactions between Li—N and Al—N are strong ionic bonds in Li3AlN2. The interaction between N and H is strong covalent bond and the interaction between Li and N is strong ionic bond in LiNH2. The calculated reaction enthalpies are −23.7 and −55.3 kJ/mol, respectively, which are in agreement with the experimental ones.
Key words: Li-Al-N-H complex; electronic structure; reaction enthalpy; first principle
