Li_2,Na_2和NaLi分子基态及低激发态的结构与势能函数

Structure and Potential Energy Function for the Ground State and Low-lying Excited State of Li_2,Na_2 and NaLi

采用群论及原子分子反应静力学方法,推导了Li2、Na2和NaLi分子基态及低激发态的电子态及相应的离解极限,运用二次组态相互作用方法(QCISD)优化计算了Li2、Na2和NaLi分子基态的平衡结构、振动频率和离解能,并对Li2、Na2和NaLi分子基态进行了单点能扫描计算,激发态则用CIS方法,给出了各分子的Murrell-Sor-bie函数形式的完整势能函数,计算出与基态和低激发态相对应的光谱常数(Be,αe,ωe和ωeχe),结果与实验数据符合得相当好.

In this paper, the electronic states of the ground state and low-lying excited electronic state dissociation limit of Li2 ,Na2 and NaLi are correctly determined based on group theory and atomic and molecular reaction statics. The equilibrium geometries, harmonic frequencies and dissociation energies of the ground state of Li2 ,Na2 and NaLi are calculated using double substitutions （QCISD）. The potential curves are scaned using the QCISD/6--311 ＋ ＋G（3df, 3pd） method for the ground state and low-lying excited electronic state using CIS method. The research has a least aquare fitted to Murrell--Sorbie function and gets the relevant optical constants of these molecule. All the calculations are in good agreement with the experimental data.