NiH2分子的结构及其势能函数

应用群论及原子分子反应静力学方法推导了NiH2分子基态的电子态及其离解极限,在MP2/6-311G水平上,优化出NiH2(3Δg)分子稳定构型为D∞h,其平衡核间距Re=0.157 3 nm、∠HNiH=180.00°,同时计算出振动频率:对称伸缩振动频率ν1=2 000 cm-1,弯曲振动频率ν2=721 cm-1和反对称伸缩振动频率ν3=1 875 cm-1.在此基础上,使用多体项展式理论方法,导出了基态NiH2分子的全空间解析势能函数,该势能函数准确地再现了NiH2(D∞h)平衡结构.

The molecular structure and potential energy function for NiH2 system

In the present paper, firstly, the electronic state and reasonable dissociation limits of NiH 2 are correctly determined based on group theory and atomic and molecular reaction statics. Moreover, using the MP2 and basis 6-311G  , we have optimized the equilibrium geometry for the ground state X 3Δ g of NiH2, which is D ∞h . The equailibrium geometry, dissociation energy and harmonic frequencies for NiH 2 have been calculated. The results show that R e (NiH)=0.157 3 nm, D e (NiH2)=9.846 eV, and ν 1,ν 2 and ν 3 are 2 000,721 and 1 875 cm -1 ,respectively. Finally, an analytical potential energy function for the ground state X 3Δ g of NiH 2 has been derived using many-obdy expansion method, Then, the potential energy function is successfully used for describing the equilibrium geometry of NiH2.