中文摘要：

采用密度泛函（DFT）中的B3P86方法,在Dunning的相关一致基组cc-PVTZ水平上,对铝氢化物Al2Hn（n=1～6）团簇的可能几何构型进行优化计算,得出最稳定构型的几何参数、电子结构、振动频率和光谱等性质参数,并给出了最稳定结构的总能量（ET）、结合能（EBT）、平均结合能（Eav）、电离势（EIP）、能隙（Eg）、费米能级（EF）和氢原子差分吸附能（Ediff）等.结果表明铝氢化物团簇基态稳定结构的电子态分别为：n为奇数为2A,n为偶数为1A;由于Al原子属于缺电子原子,能与等电子原子H化合,通过氢桥键形成含多中心键的氢化物,本文优化计算发现,铝氢化物团簇最稳定的构型中都存在氢桥键,这是铝氢化物的奇异结构特征.最后分析铝氢化物团簇的平均结合能、电离势、能隙和费米能级等动力学和红外光谱特性,说明Al2Hn（n=1～6）团簇中Al2H6最稳定,H—Al桥键键长比端键更长,最强峰红外光谱强度最大.

英文摘要：

The possible geometrical structure of aluminum hydride Al2Hn （n = 1---6） clusters has been opti- mized computation,based on density functional theory B3P86 method and at the Dunning related consistent base group cc - PVTZ level. The configuration geometric parameter, electronic structure, vibrational frequency and spectrum of the most stable structure has been obtained, and given total energy （ ET） , binding energy （ EBT ） , av- erage binding energy （ Eav ）, ionization potential （ EIP） , energy crack （ Eg ）, Fermi level （ EF ） and so on. The re- sults indicate that the ground state of aluminum hydride clusters all are 1 heavy condition, the electronic state is when n is odd number and it is when n is even number, respectively. In all aluminum hydride clusters, they be- long to hydrogen bridge type. The ultimate analysis of the infrared spectrum covers the average binding energy, the ionization potential,the energy gap and Fermi level and their characteristic. It has shown that A12H6 is the most stable molecule in （Al2Hn ） （n = 1-6 ）, the H - Albridge bond key length is longer than that of the terminal linkage, while the infrared intensity of strongest peak is of maximal value.