Li_2O基态分子的结构与势能函数

Structure and potential energy function of Li_2O molecule

使用二次组态相互作用方法,以AUG-cc-pVTZ为基组优化出Li2O分子的稳定构型,其电子状态为X1∑.Li2O是近似直线形分子(∠LiOLi=179.92°),属于Cs构型.其离解能De=10.238 eV,谐振频率:v1=151.53 cm-1、v2=810.73 cm-1、v3=1065.55 cm-1.根据原子分子反应静力学原理得到Li2O分子可能的电子状态和离解极限.在此基础上,运用多体展式理论方法推导出了Li2O基态分子的解析势能函数,正确地反映了其平衡构型特征.

QCISD（T）/AUG-cc-pVTZ methods have been used to optimize the structure for the ground state of Li2O（ Cs, X^1 ∑ ） molecule. For Li2O molecule, the equilibrium geometry, dissociation energy and harmonic frequencies are calculated, the results show that ∠LiOLi = 179.92°, De = 10. 238 eV and vl, v2 and v3 are 151.53 cm^-1, 810.73 cm^-1, 1065.55 cm^-1, respectively. The possible electronic state and its reasonable dissociation limit for the ground state of Li2O molecule is determined based on atomic and molecular reaction statics. The analytic potential energy function of Li20（ Cs, X^1 ∑ ） molecule was derived by many-body expansion theory which is successfully used for describing the equilibrium geometry of Li2O.