Al_2^(n±)(n=0,1,2)分子离子势能函数和能级的研究

Study on potential energy functions and energy level of AI_2^(n±)(n=0,1,2)

耦合团簇理论的CCSD(T)/CC-PVQZ和组态相互作用理论的QCISD(T)/CC-PVQZ两种方法对Al_2~n±(n,0,1,2)分子离子的势能函数和能级进行了研究.计算结果表明:Al_2~n(n=0,±1,±2)均可能稳定存在,其稳定态的电子态分别是:~3∑_g(Al_2)、~2∑_g(Al_2^+),~4∑_g(Al_2^-),~3∑_g(Al_2^(2-))和~3∑_g(Al_2^(2+)).其中Al_2^(2+)的势能函数曲线呈"火山态"型.本文用四参数Murell-Sorbie势拟合了除Al_2^(2+)外的四个分子离子的势能函数,该函数对这些曲线拟合得很好,但它对Al_2^(2+)的势能函数的拟合较差,本文用七参数Murell-Sorbie势拟合了Al_2^(2+)分子亚稳态双原子分子离子势能函数,其拟合曲线与势能函数曲线符合得很好.同时讨论了电荷对势能函数和能级的影响.

The potential energy functions and energy level of AI~~ （n = 0,1,2） have been analyzed by CCSD（T）/CC-PVQZ and QCISD（T）/CC-PVQZ. The results show that all of AI~ （n= 0, ＋ 1, ~ 2） can exist stably. The electronic states of their stable states are 3 ^（A12） 2 ~,（A1＋ ） ~ ~2~ （AI^-） ,3 ~g（Al^- ） and3 ~]g（Al~ ＋） respectively. Among them, the potential energy curves of AI~＋ are like a ＂volcano＂. The potential energy curves of AI~＋ have been fitted with the seven-parameter Murell-Sorbie functions. It has been found that the fitting cures of the meta-stable ions AI~＋ are well in accordance with its potential en- ergy curve. The other potential curves are fitted with the four-parameter Murell-Sorbie functions. They are also well in accordance with their potential energy curves. At the same time, the effect of charge on the potential energy functions and energy levels have been discussed.