氟化氢团簇(HF)n(n=2～8)拓扑性区别氢键构型的图论列举法和量子化学计算法研究

Investigation of Topology-distinct Stable Structures for Hydrogen Fluoride Clusters (HF)_n(n=2—8) by the Methods of Graph Theoretical Enumerations and Quantum Chemical Calculations

利用提出的图论程序列举出氟化氢团簇（HF）n（n=2-8）所有可能存在的拓扑性区别氢键构型,通过精密调查获得有可能存在的拓扑性区别构型,发现了满足HF团簇稳定性的若干条件,在这些条件的基础上编写FORTRAN程序和Python语言执行程序,再用画图软件包Graph Viz2.37自动画出对应的有向图或条件性有向图.以对应的有向图作理论框架,分别利用从头算法Moller-Plesset（MP2）二级微扰方法和密度泛函理论（DFT）方法 B3LYP计算水平的6-31G＊＊（d,p）基组对氟化氢团簇（HF）n（n=3-7）所有拓扑性区别条件性有向图对应的初始结构进行结构优化并作振动频率分析,获得氟化氢团簇（HF）n（n=2-7）的最稳定构型,发现了氟化氢团簇的五聚体（HF）5、六聚体（HF）6和七聚体（HF）7等一些新的稳定结构.

A graph theoretical procedure to generate all the possible topology-distinct structures for hydrogen fluoride（HF） clusters was presented and all the possible topology-distinct structures for hydrogen fluoride（HF）n（n = 2—8） clusters were enumerated in this work. On the basis of the restrictions found,FORTRAN program was designed and executed by Python program,and the corresponding diagraphs or restrictive digraphs were drawn by means of free graph visualization software, Graph Viz 2. 38 for HF cluster（HF）n（n = 2—8）. Within the theoretical framework of the corresponding digraphs or restrictive digraphs,all the topology-distinct local minima for（HF）n（n = 3—7） were optimized and analyzed by means of ab initio method and density functional theory（DFT） method at the level of MP2/6-31G＊＊（d,p） and B3 LYP/6-31G＊＊（d,p）,respectively. The local minimum structures for（HF）n（n = 3—7） are the same as those in the previous works. For HF pentamer,hexamer and heptamer,some new local minimum structures were obtained.