【摘要】 采用基于密度泛函理论(DFT)的平面波赝势(PW-PP)方法,计算Li-Al-N-H系络合物贮氢反应中各个化合物的晶胞参数、电子结构、生成焓和贮氢反应的反应焓。结果表明:Li3AlN2的Li—N、Al—N键主要为离子键,LiNH2的N—H键主要为共价键,Li—N键主要为离子键;298K时贮氢反应的反应焓计算值分别为-23.7和-55.3kJ/mol,与实验值均符合得较好;反应中各固态、气态物质的晶胞的结构优化后的晶格常数、键长与键角等与相应的实验值均符合较好。更多还原

【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.更多还原