Cs-Mg-H合金的形成能力与成键机制研究  

Formation ability and bonding mechanism of Cs-Mg-H alloy

作　　者：邓永和[1] 尹凤娥[2] 容青艳[1] 

机构地区：[1]湖南工程学院理学院,湘潭411104 [2]中南林业科技大学土木工稃与力学学院,长沙410004

出　　处：《中国科学：物理学、力学、天文学》2010年第2期213-218,共6页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：湖南省教育厅优秀青年项目基金资助(编号:09B021)

摘　　要：采用基于密度泛函理论第一性原理的Vienna Abinitio Simulation Package(VASP)软件研究了CsMgH3,Cs4Mg3H10和Cs2MgH4氢化物的晶体结构、反应焓和电子结构.结果表明CsMgH3,Cs4Mg3H10和Cs2MgH4都能直接由单质Cs和Mg在H2中反应生成,其中Cs4Mg3H10的形成能力最强;态密度和电荷密度的分析与讨论表明了Mg和H的成键机制为离子键伴随着显著的共价键.Theoretical study of structure, reaction enthalpies and electronic structure of the CsMgH3, Cs2MgH4 and Cs4Mg3H10 compounds were performed using the first-principles method based on the density functional theory with generalized gradient approximation. The reaction enthalpies of CsMgH3, Cs2MgH4 and Cs4Mg3H10 showed that the ternary hydrides could be synthesized by direct reaction between Cs and Mg in hydrogen atmosphere, and formation ability of Cs4Mg3H10 was more strong than CsMgH3 and Cs2MgH4. The obtained densities of states and charge density distribution were analyzed and discussed to assess the microscopic mechanism of bond in the compounds. The character of ionic bonds with noticeable covalence bonds between Mg and H was discovered.

关 键 词：第一性原理计算 Cs-Mg-H 反应焓 态密度 电荷密度 形成能力 成键机制 

分 类 号：TG146.265[一般工业技术—材料科学与工程]