N2O异构体结构与解析势能函数

Structure and analytic potential energy function of N_2O isomer

在B3P86/cc-PVTZ水平上,对N2O异构体进行优化计算,得出N2O基态的单重态能量最低,其稳定构型为C∞v构型,平衡核间距R1=0.1121nm,R2=0.1177nm,α=180°,能量为-185.1188a.u.同时计算出基态的简正振动频率ω1(Π)=601.5010cm-1,ω2(Σg)=1295.8518cm-1和ω3(Σu)=2287.0627cm-1.在此基础上,使用多体项展式理论方法,导出NO分子的全空间解析势能函数,该势能函数准确再现了NO(C)平衡结构.

The equilibrium geometry of N2O, NO and N2 molecules have been calculated on the computational levels of density functional theory. The Murrell-Sorbie analytic potential energy function of NO and N2 molecules have been derived through the least-square fitting to ab initio data. Similarly, the harmonic frequency has been calculated and the analytic potential energy function of linear molecule N2O isomer is derived by many-body expansion theory for the first time.