掺杂V对LiNH_2解氢性能的第一原理计算

First Principle Calculation of Doped V Dehydrogenating Properties of LiNH_2

采用基于密度泛函理论的第一性原理赝势平面波方法,研究了V元素掺杂对LiNH2的电子结构和解氢性能的影响。计算结果显示,V元素掺杂LiNH2晶体模型的负合金形成热减少,LiNH2体系结构的稳定性减弱,合金化增强了体系的解氢能力。Mulliken集居数、电子态密度与电子密度的进一步分析发现:掺杂V以后,通过电荷补偿,N与H之间离子性相互作用增强,共价性相互作用减弱;费米能级(EF)处键峰值增大,能隙ΔEH-L变窄,LiNH2的解氢能力提高。

Using the plane waves ultrasoft pseudopotential method based on the first principles of DFT, the in- fluence of doping V on the electronic structure and dehydrogenation properties of LiNH2 was studied. The results show that the negative heat of formation there are weaken the structural stability, alloying elements befit to improve the de- hydrogenating properties of LiNH2. After comparing the mulliken populations and the densities of states and the charge distribution, it is found that the catalysis effect of V on dehydrogenating kinetics of LiNH2 may attribute to the changes of N and H between ionic interaction is enhanced and covalent interaction weakened, the Fermi level （EF） place peak value of bond are increased and the energy gap near the Fermi levelΔE,-L are narrows.