夹心多核茂合物Cp_2Mg_n结构和储氢性能的第一性原理研究

First-principles Study on the Structure and Hydrogen Storage Properties of Sandwich-type Multi-metallocenes

使用基于密度泛函理论(DFT)的DMol3程序包,研究了夹心多核茂合物Cp2Mgn的几何结构、电子结构和储氢性能。研究表明:夹心原子对体系结构影响微弱;Mg-Mg间形成共价σ单键,Mg-Cp间形成离域π共价键;Cp2Mg2和Cp2Mg3最多可分别吸附氢分子4个和10个,吸附能分别为0.252 e V/H2和0.291 e V/H2,储氢量分别为4.32wt%和9.03wt%。

With respect to first-principles calculation based on density functional theory（ DFT）,the electronic structure, geometry structure and ability of absorbing hydrogen molecule of the multimetallocenes Cp2Mgn（ n = 1,2,3） were investigated. The results indicate that doped Mg atoms have little effect on the geometrical structure of multi-metallocenes; the Mg-Mg bond is a σ covalent single bond and there is a delocalized π covalent bond between the Mg and Cp; Cp2Mg2 and Cp2Mg3can adsorb four and ten hydrogen molecules respectively; the binding energy is 0. 252 e V / H2 and 0. 291 e V / H2; the corresponding gravimetric hydrogen-storage capacities are 4. 32wt% and 9. 03wt%.