六氨氯化镁分子与电子结构的理论化学计算  

Theoretical study of molecular and electronic structure of MgCl_2·6NH_3

作　　者：宋兴福[1] 刘够生[1] 汪瑾[1] 于建国[1] 

机构地区：[1]华东理工大学资源过程工程研究所,上海200237

出　　处：《计算机与应用化学》2008年第9期1115-1118,共4页Computers and Applied Chemistry

基　　金：国家科技部"十五"科技攻关项目(2004BA311A10);上海市重点学科建设项目资助(B506).

摘　　要：为了从分子水平了解六氨氯化镁的结构,采用RHF、B3LYP和MP2等量子化学方法分别对六氨氯化镁的几何结构全优化,获得了多种基组水平的平衡几何构型。计算结果表明,六氨氯化镁中的6个氨在原子核与其它电子形成的平均势场中分裂,分为两级,第一级4个氨,第二级2个氨,当外界条件变化时,最有可能是脱去4个氨分子,升温后再脱去另外2个氨,这一结论符合实验结果一致。采用B3LYP算法在不同基组大小上的计算表明,基组3-21G可以获取基本满意的计算结果。在B3LYP/6-31G(d)基础上,增加极化基组或弥散函数后对计算结果无明显改善。RHF, B3LYP and MP2 methods were used to study the molecular and electronic structure of MgCl2· 6NH3 results show that in molecule MgCl2 · 6NH3, the six ammonia molecules are not entirely equal, they are classified into two minor grading equilibrium. Four of them are the first grade, which are long bond length with center Mg atom; the other two are the second grade, which are short bond length with center Mg atom. The results mean that, by heat decomposition, four ammonia may be removed in the first stage, then two ammonia in the second stage. The results are in good agreement with experiments. Results by B3LYP method on different basis sets show that 3-21G basis set can obtain good results. Structure parameters calculated by polarized basis sets and diffuse functions show that no improvement are obtained.

关 键 词：六氨氯化镁 分子结构 基组 量子化学 

分 类 号：O626[理学—有机化学]