NH_3分子在LiH(100)表面吸附的第一性原理研究  

First principles study of NH_3 molecule adsorption on LiH(100) surfaces

作　　者：吕晓霞[1,2] 陈玉红[1,2] 董肖[2] 

机构地区：[1]兰州理工大学甘肃省有色金属新材料省部共建国家重点实验室,兰州730050 [2]兰州理工大学理学院,兰州730050

出　　处：《原子与分子物理学报》2012年第4期689-693,共5页Journal of Atomic and Molecular Physics

基　　金：甘肃省自然科学基金(1010RJZA042);兰州市科技项目(2011-1-10);兰州理工大学博士基金(BS10200901)

摘　　要：采用第一性原理方法研究了NH_3分子在LiH(100)晶面的表面吸附情况.通过研究LiH(100)/NH_3体系的吸附位置、吸附能和电子结构,发现NH_3分子在LiH(100)晶面主要是化学吸附,初始位置为NH_3分子中N-H键在Li顶住时失去一个H原子,并在LiH(100)面形成NH_2基,其吸附能为0.511 eV,属于强化学吸附,吸附作用最强.此时NH_2基与附近H原子和Li原子之间为离子键作用,NH_2基中N—H键为共价键;NH_3分子中另一个H原子与LiH表面的一个H原子形成一个H_2分子逸出表面.H_2分子中H-H键为明显的共价键.The adsorption of NH3 on LiH（100） crystal surfaces was studied by first principles method. The preferred adsorption sites, adsorption energy, dissociation energy and electronic structure of the LiH（100）/NH3 systems were calculated separately. It is found that chemical adsorption happened mainly when NH3 molecules are on the LiH（100） crystal surfaces. When NH3 is adsorbed on the Li top site, NH2 is formed on the LiH （100） crystal surfaces after loss of H atom, the calculated adsorption energy, 0.511 eV, belongs to strong chemical adsorption, then the interaction is strongest. The interaction between NH2 and the neighboring Li、H are ionic. The covalent bonds are formed between N and H atoms in NH2. One H2 molecule is formed by another H atom in NH3 and H atom from LiH（100） crystal surfaces. The covalent bonds are formed between H and H atoms in H2.

关 键 词：第一性原理 LiH(100) NH3 吸附 

分 类 号：O[理学]