OCN2分子的光谱常数和非谐力场的从头算研究

Ab Initio study of spectroscopic constant and anharmonic force field of OCN2

摘要:

基于密度泛函理论中的B3LYP，B3p86和B3pw91三种方法和二阶微扰（MP2）方法分别结合Dunning相关一致基组cc-pVnZ (n=D,T) 和 aug-cc-pwCVDZ对OCN2分子进行了理论研究，在选定的方法和基组的理论水平下计算分子的平衡态结构参数，然后在此结构基础上在同样的理论水平下理论计算分子平衡态光谱常数以及非谐力场。将理论计算的的平衡态几何结构、基态转动常数和离心畸变常数等与已有的理论数据和实验数据进行了比较，同时对振转相互作用常数，三阶和四阶力常数、科里奥利耦合常数和部分离心畸变常数进行合理的预测。

Abstract:

we calculate the equilibrium geometry structure of OCN2 by using B3LYP, B3p86, B3pw91 and MP2 methods combining  with cc-pVnZ (n=D,T) and aug-cc-pwCVDZ basis sets. On this base, we obtain the spectroscopic constants and anharmonic force field of OCN2. Then we compared the results of equilibrium geometry structures, rotational constants, vibration-rotation interaction constants that we obtained from the calculation with the relevant experiment and theoretical data. In addition, we also predict the quartic and sextic centrifugal distortion constants, coliolis constants, third-order and forth-order force constants of OCN2.