贮氢材料VH_x(x=0,1,2)电子结构的DV-X_α研究  

Quantum chemical DV-X_α study on electronic structure of hydrogen storage materials VH_x(x=0, 1, 2)

作　　者：李荣[1] 周上祺[1] 梁国明[2] 刘守平[1] 陈昌国[1] 

机构地区：[1]重庆大学材料科学与工程学院,重庆400044 [2]重庆师范大学化学学院,重庆400047

出　　处：《中国有色金属学报》2005年第3期391-396,共6页The Chinese Journal of Nonferrous Metals

基　　金：重庆市自然科学基金资助项目(CSTC2004BB4169); 重庆师范大学博士科研基金资助项目

摘　　要：利用电荷自洽离散变分 Xα(SCC DV Xα)方法计算了钒基固溶体中钒氢反应前后钒及其氢化物(VHx,x=0, 1, 2)的电子结构。对净电荷、键级和电子密度差的分析表明: VH和 VH2 中 V—H键之间既有离子性又有共价性的相互作用。VH2 中V—H之间的键级比 VH中 V—H之间的键级小, 说明 VH2 中的 H容易释放出来。对能级结构、态密度和价轨道集居数的分析表明, 氢化物VH中是V的4s轨道和H的1s轨道作用成键; 氢化物VH2 中是V的4s、3d轨道和H的1s轨道作用成键; VH比VH2 的费米能级低, 说明VH更稳定。解释了VH2 中的氢不能全部放出的原因。The electronic structure of metallic V before and after reaction of V—H and its hydrides(VH_x, x=0, 1, 2) in vanadium base solid solution was calculated by a quantum chemical method(SCC-DV-X_α). By analyzing net charge, bond level and electron density difference, the following results are obtained: there exists interaction between V—H bands interaction which has not only ionic but also covalent property in hydride VH and VH_2, bond level between V—H in hydrideVH_2 is weaker than that in VH, which proves that H in VH_2 is released more easily than in VH. By analyzing the energy level structure and electron density of states and the electron occupation numbers in valence orbits, the result show that the former V 4s-H 1s interaction is bonding-type, and also the latter V 3d, 4s-H 1s interaction is bonding-type. Fermi energy level in VH is weaker than that in VH_2, which proves that VH is more stabilization, and explains the reason why H_2 is not all released.

关 键 词：钒氢化物 电子结构 SCC-DV-Xα方法 

分 类 号：O641.121[理学—物理化学]