The possible geometrical structures of boron hydride (B2 Hn )(n=1-6) were optimized based on density functional theory of B3P86 method and the Dunning related consistent base group cc-pVTZ level .The configuration geometric parameter ,electronic structure and vibration frequency of the most stable structure were obtained ,and the total energy ( ET ) , binding energy ( EBT ) , average binding energy ( Eav ) , ionization potential (EIP ) , energy gap (Eg ) , Fermi level (EF ) , hydrogen atom differential adsorption energy (Edif ) and so on were given .The results show that the electronic states in ground state of boron hydride are 1 heavy condition w hen n is even number and they are 2 heavy condition w hen n is odd number ,respectively .In all boron hydrides , there is hydrogen bridge linkage .T hrough analyzing electronic characteristic of the most stable structure ,it is found that the ionization potential and energy gap are maximal values ,the H-B bridge bond key is longer than terminal linkage ,the infrared intensity of the strongest peak is maximal value of B2 H6 in B2 Hn (n=1-6) which explains that B2 H6 is the most stable boron hydride ,and the hydrogen atom differential adsorption energy is the largest and the hydrogen storage performance is the best .%采用密度泛函（DFT ）B3P86方法，结合Dunning 的相关一致三重基cc-pVTZ ，优化计算硼氢化物（B2 Hn ）（n＝1～6）可能的几何构型，得出最稳定结构的几何参数、电子结构和振动频率等参数，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（ Edif ）等。结果表明，硼氢化物基态稳定结构的电子态分别为：n为奇数时为双重态2 A ，n为偶数时为单重态1A。由于B原子属于缺电子原子，能与等电子原子 H化合，通过桥键形成多中心键的氢化物，优化计算发现，硼氢化物最稳定结构都存在桥键，且n为奇数的桥键作用比相邻偶数的强。通过分析最稳定结构的电子特性发现，B2 Hn （n＝1～6）中B2 H6的电离势和能隙最大，桥键比端键长，红外光谱强度最大，说明该硼氢化物最稳定，且其氢原子差分吸附能最大，储氢性能相对最好。
展开▼
