摘要
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(B2Hn)(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(Ediff)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1 A。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,B2Hn(n=1～6)中B2H6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。
The possible geometrical structures of boron hydride （Ba H.） （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 （E.v）, ionization potential （Ep）, energy gap （E）, Fermi level （EF）, hydrogen atom differential adsorption energy （Edff） and so on were given. The results show that the electronic states in ground state of boron hydride are 1 heavy condition when n is even number and they are 2 heavy condition when n is odd number, respectively. In all boron hydrides, there is hydrogen bridge linkage. Through 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 intensityof the strongest peak is maximal value of B2 H6 in B2 H. （n= 1-6） which explains that B2H6 is the most stable boron hydride, and the hydrogen atom differential adsorption energy is the largest and the hydrogen storage performance is the best.
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2013年第11期1925-1930,共6页
Atomic Energy Science and Technology
基金
国家自然科学基金资助项目(11147158
10965002)
江西省自然科学基金资助项目(2010GQW0031)
江西省教育厅科技项目资助(GJJ12483)
关键词
密度泛函理论
硼氢化物
电子特性
density functional theory
boron hydride
electronic characteristic
