碱金属Li,Na,K,Rb,Cs,Fr的ns^2S_(1/2),np^2P_(1/2,3/2),nd^2D_(3/2,5/2)和nf^2F_(5/2,7/2)里德伯能级理论研究

Theoretical study of the Rydberg series energy levels of ns^2S_(1/2),np^2P_(1/2,3/2),nd^2D_(3/2,5/2) and nf^2F_(5/2,7/2)for alkali-metal Li,Na,K,Rb,Cs and Fr

本文在多通道量子数亏损理论(MQDT)框架下,利用相对论多通道理论(RMCT),分别在冻结实近似、考虑△l=-1的偶极极化效应、△l=+1的偶极极化效应、△l=±1的偶极极化效应、伸缩模效应以及同时考虑偶极极化效应和伸缩模效应等不同层次近似下,系统地计算了碱金属Li,Na,K,Rb,Cs和Fr七个里德伯系列的能级,即ns^2S_(1/2),np^2P_(1/2),np^2P_(3/2),nd^2D_(5/2),nf^2F_(5/2)和nf^2F_(7/2).计算结果表明,电子关联效应对碱金属原子的里德伯能级的影响很大.总的来说,偶极极化效应比伸缩模效应重要,而在偶极极化效应中,△l=+1的偶极极化效应比△l=-1的偶极极化效应重要.但对于Na的ns^2S_(1/2),(nd^2D_(3/2),nd^2D_(5/2)里德伯系列的能级,和Li的(np^2P_(1/2),np^2P_(3/2)里德伯系列的能级,是伸缩模效应比较重要.

In the frame work of multi-channel quantum defect theory,the energy levels of Rydberg series of ss^2S_（1/2）,np^2P_（1/2）,np^2P_（3/2）, nd^2D_（3/2）,nd^2D_（5/2）,nf^2F_（5/2） and nf^2F_（7/2） of alkali-metal atom are calculated by the relativistic multi-channel theory,in five different approximations,i.e.,frozen core approximation,with consideration of Al =—1 dipole polarization effect,Al = ＋1 dipole polarization effect,Al =±1 dipole polarization effect,stretch effect,and both dipole polarization effects and stretch effect,respectively. The present calculations show that electron correlation effect plays an important role in the energy level of Rydberg series. In summary,dipole polarization effect is more important than the stretch effect,and the Al = ＋1 dipole polarization effect is more important than Al =—1 dipole polarization effect.However,stretch effect is more important for energy levels of both Rydberg series ns^2S_（1/2）,（nd^2D_（3/2）,nd^2D_（5/2）） of Na,and Rydberg series（np^2P_（1/2）,np^2P_（3/2）） of Li.