BeS分子基态与激发态势能函数和光谱性质的理论研究

Theoretical study on ground state and excited state potential function and spectral properties of BeS molecules

基于原子分子反应静力学的原理,推导出了BeS分子基态X^(1)Σ^(+),第一简并激发态A^(1)Π和第二激发态B 1Σ^(+)的离解极限。利用SAC/SAC-CI方法结合D95++,6-311++G,6-311++G,CC-PVDZ这4个基组,分别对BeS分子的X^(1)Σ^(+),A^(1)Π和B 1Σ^(+)态进行了几何优化,从中优选出6-311++G基组,用SAC方法对基态,SAC-CI方法对激发态进行了单点能扫描,通过Murrell-Sorbie函数拟合,获得了X^(1)Σ^(+),A^(1)Π和B 1Σ^(+)的力常数和光谱常数,计算的结果与实验数据非常吻合,进一步确认了所得解析势能函数的可靠性和准确性。

Based on the principle of atomic and molecular reaction statics,the dissociation limits of the ground state X^(1)Σ^(+),the first degenerate excited state A^(1)Πand the second excited state B 1Σ^(+)for BeS molecule are derived.The geometric optimization of those states are performed by using SAC/SAC-CI method combining D95++,6-311++G,6-311++G,CC-PVDZ basis sets,respectively.The single-point energy scan are calculated by adopting 6-311++G basis set,the SAC method for the ground state,and the SAC-CI method for excited state.The Murrell-Sorbie function is fitted to obtain the force constants and spectral constants of X^(1)Σ^(+),A^(1)Πand B 1Σ^(+),and the calculated results of the SAC-CI method are in good agreement with the experimental data,which further confirms the reliability and accuracy of the analytical potential function.