中文摘要：

采用基于密度泛函理论“总体能量赝势平面波方法”的CASTEP总能计算软件包，通过LiNH2晶胞将Li置换成Mg和Nb及其移走H所需能量及几何、电子结构、负合金形成热的计算，发现添加Mg和Nb使LiNH2体系负合金形成热减少，表明体系相结构稳定性变差，预示着解氢能力得到改善。通过电子态密度（DOS）与电子密度的进一步分析发现，添加Mg和Nb提高LiNH2解氢能力的主要原因在于Mg和Nb与其周围的H相互作用不明显，而使NH之间的成键作用减弱，从而提高了LiNH2体系的解氢能力。

英文摘要：

Based on density functional theory ＂total energy pseudopotential plane-wave method＂ CASTEP（cambridge serial total energy package） the total energy calculations packages, through the LiNH2 cell will replace Li atoms into the Mg and Nb atoms and the energy required to remove the H atom and the geometry, electronic structure, the formation of negative thermal calculations. Found that adding Mg and Nh alloy to form a hot LiNH2 system to reduce the negative, indicating that structural stability system phase variation, indicating a solution of hydrogen capacity to be improved. Further through the electronic density of states（IDOS） and electronic density further analysis found that, the main reason of adding a solution of Mg and Nb in improving dehydrogenating property of LiNH2 lies in the interaction of Mg and Nb with H atoms around their is not obvious, while the ability between NH bond the weakened role of the increase LiNH2 system solution of hydrogen capacity.