Theoretical Investigation On The Long-range Interactions Of Alkali-metal Atoms

In recent years, with the advances in laser cooling and trappingtechnology and the realization of Bose-Einstein condensation for someelements, there has been increased interest in investigating the atomicpolarizabilities and the dispersion coefficients. On the background, thelong-range interactions of the alkali-metal atoms are studied theoretically.In general, by combining the model potential method with thevariationally stable procedure, we have systemic investigations on thelong-range interactions of the ground-state alkali-metal atoms. Thisapproach has two typical advantages: the model potential method isconvenient to determine the ground-state wave function of alkali atoms;the results of the polarizabilities and dispersion coefficients, calculated bythe variationally stable method, have a high precision and are fastconvergent.In the concrete, the present work consists of two aspects: Firstly,based on the model potential and the experimental values of the bindingenergies of the valence electron, the simple wave functions of alkaliatoms are given, and the variationally stable procedure of Gao andStarace is employed to evaluate the multipolar polarizabilities of Li, Na,K, Rb, Cs, the two-body dispersion coefficients of homonuclear andheteronuclear interactions from C₆to C₄₀, as well as the three-bodydispersion coefficients Z（L₁,L₂,L₃）（up to L_i=5）. The calculated values of the coefficients C_n（n<24） and Z（L₁,L₂,L₃）（L_i<3） agree well with thosereported in the literature. In addition, the results of C_n（n>24） andZ（L₁,L₂,L₃）（L_i>3） are reported for the first time. Secondly, another formof the ground-state wave function of Na is obtained on the basis of theweakest bound electron potential model theory. The variationally stableprocedure is then used to evaluate the static multipolar polarizabilities ofNa, and the two-body dispersion coefficients for the Na-Na system.The two achievements mentioned above have been published in J.Chem. Phys.. The present method, which combines the model potentialmethod with the variationally stable procedure, can be generalized tostudy the long-range interactions of other atomic systems.