D_2分子X^1Σ_g^+,B_1Σ_u^+和C^1Π_u态的势能函数

Potential Energy Functions for the Electronic States X^1Σ_g^+,B^1Σ_u^+ and C^1Π_u of Molecule D_2

使用SAC/SAC-C I和D95++**、6-311++g**及cc-PVTZ基组,分别对D2分子的基态X1Σg+、第二激发态B1Σu+和第三简并激发态C1Πu的平衡结构和谐振频率进行优化计算.对所有计算结果进行比较,得出cc-PVTZ基组为最优基组.运用cc-PVTZ基组和SAC方法对基态X1Σg+、SAC-C I方法对激发态B1Σu+和C1Πu进行单点能扫描计算,并用正规方程组拟合Murrell-Sorb ie函数,得到相应电子态的势能函数解析式,由得到的势能函数计算了与X1Σg+、B1Σu+和C1Πu态相对应的光谱常数,结果与实验数据较为一致.

The energies, equilibrium geometries and harmonic frequencies of the ground state X^1∑g^＋, the second excited state B^1∑u^＋ and the third degenerate excited state C^1∏u . of molecule D2 have been calculated using the methods SAC/SAC-CI with the basis sets D95 ＋ ＋ ＊ ＊ , 6-311 ＋ ＋ g ＊ ＊ and cc-PVTZ. Comparing the three basis sets above-mentioned, the conclusion is gained that the ba- sis set ec-PVTZ is the most suitable for the energy calculation of molecule D2. The whole potential curves for these three electronic states are further scanned adopting SAC/cc-PVTZ method for the ground state and SAC-CI/cc-PVTZ method for the excited states, then a least square is applied to fit the Murrell-Sorbie function. Therefor, the analysis formulas of potential energy function are also obtained for the corresponding electronic state. The spectroscopy constants are calculated, and the results were in better agreement with experimental data.