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 × 10³, 4.275 ×10³, and 4.275 × 10³ K. The results in the vapor phase are by and large somewhat lower than those in free space. (author)