NiH_2(~3Δ_g)基态的全空间解析势能函数

Analytical Potential Energy Function in the Whole Space for the Ground State (~3Δ_g) of NiH_2

应用群论及原子分子反应静力学方法推导了NiH2 的电子态及其离解极限 ,在MP2 / 6 311G 水平上 ,优化出NiH2 ( X 3Δg)分子稳定构型为D∞h,其平衡核间距Re=0 .15 73nm ,∠HNiH =180° ,同时计算出振动频率 :对称伸缩振动频率υ1=2 0 0 0cm-1,弯曲振动频率υ2 =72 1cm-1和反对称伸缩振动频率υ3=1875cm-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)

In this paper, firstly, the electronic state and its dissociation limit 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 3Δ g of NiH 2, which is D ∞h. The equilibrium 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(NiH 2)=9.846 eV, and υ 1, υ 2 and υ 3 are 2 000, 721 and 1 875 cm -1, respectively. Finally, an analytical potential energy function for the ground state 3Δ g of NiH 2 has been derived using many-body expansion method. Then, the potential energy function is successfully used for describing the equilibrium geometry of NiH 2.