Binding Properties of Some Alkali Metal Vapors: Specifically Lithium-7 (⁷Li), Soduim-23 (²³Na) and Potassium-39 (³⁹K)

In this work, the binding energy of three alkali-metal molecules, namely, lithium-7 (7Li2), sodium-23 (23Na2), and potassium-39 (39K2), is calculated in both free space and the vapor phase. In free space, the Lippmann-Schwinger equation is solved for negative-definite eigenenergies using a highly effective matrix-inversion method with a symmetrized kernel. In the vapor, two medium effects are taken into account: the effective atomic mass, which is somewhat larger than the ‘bare’ mass and therefore enhances the binding; and the effective binary interaction, with less overall attraction than the ‘bare’ interaction. In free space, the binding energies of the respective molecules are, in units of (103 K): 5.304, 2.936, and 2.522. The corresponding experimental results are 6.150 x 10³ K, 4.275 x10³ K, and 4.275 x 10³ K. The results in the vapor phase are by and large somewhat lower than those in free space.