SiH,SiD,SiT分子基态(X2Π)的结构与解析势能函数

Structures and analytical potential energy function of the ground-states of SiH,SiD,SiT molecules

摘要: 利用群论及原子分子反应静力学的有关原理,推导了SiH(SiD,SiT)分子基态的电子态和合理的离解极限.采用量子力学从头算法,应用二次组态相互作用QCISD/6-311g(df,2pd)方法对SiH,SiD,SiT的基态平衡结构和谐振频率进行了优化计算.并使用该方法和基组对SiH(SiD,SiT)分子的基态进行了单点能扫描计算,用正规方程组拟合了Murrel-Sorbie势能函数,得到了该态的完整的势能函数.从得到的势能函数计算了基态的光谱常数,结果与实验数据较为一致.

Abstract: The molecular reaction dynamics theory and group theory were used to attain the reasonable dissociation limits of the X2Π state of SiH,SiD,SiT molecules.The equilibrium separations,the harmonic frequencies and the dissociation energies about the X2Π states have been calculated by quantum mechanical ab initio method in the level of QCISD/6-311g(df,2pd).The whole potential curves for ground states are scanned,then has a least squares fitted to the analytic Murrel-Sorbie potential function form.Last the spectroscopy constants and force constants are calculated,which are in good agreement with the experimental data.