摘要
利用SAC/SAC-CI方法,使用D95(d)、6-311G**及cc-PVTZ等基组,对LiH分子的基态(X1Σ+)、第一激发态(A1Σ+)及第二简并激发态(B1Π)的平衡结构和谐振频率进行了优化计算.通过对三个基组的计算结果的比较,得出了D95(d)基组为三个基组中的最优基组的结论;使用D95(d)基组,利用SAC的GSUM(GroupSumofOperators)方法对基态(X1Σ+)、SAC-CI的GSUM方法对激发态(A1Σ+和B1Π)进行单点能扫描计算,用正规方程组拟合Murrell-Sorbie函数,得到了相应电子态的完整势能函数;从得到的势能函数计算了与基态(X1Σ+)相对应的光谱常数,结果与实验数据较为一致.
The energies, equilibrium geometries and harmonic frequencies of the three electronic states （the ground state X ^1 ∑^＋ , the first excitation state A ^1∑ ^＋ and the second excitation degenerate state B ^1П） of LiH molecule have been calculated by using the GSUM （Group Sum of Operators） method of SAC/ SAC-CI with the basis sets D95 （d）, 6-311G＊＊, and cc-PVTZ. Comparing with the above-mentioned three basis sets, the conclusion is gained that the basis set D95（d） is the most suitable for the energy calculation of LiH molecule. The whole potential curves for these three electronic states are further scanned, using SAC/D95 （d） method for the ground state and SAC-CI/D95（d） methods for the excited states. Murrell-Sorbie function were fitted using a least square and then the spectroscopy constants are calculated, which are in good agreement with the experimental data.
基金
ProjectsupportedbytheNationalNaturalScienceFoundationofChina(10376022).ProjectsupportedbytheNationalNaturalScienceFoundationofChina(10376022).
