Binding energy for some atomic and exciton complex systems

The general recursion relation developed previously for the exciton---ionized-donor complex has been applied to different atomic and exciton complex systems. The calculated values of the energies in the helium atom and the hydrogen negative ion are in good agreement with those obtained by Pekeris. The binding energy for the excitonic-molecule positive ion has been calculated as a function of the mass ratio σ=mₑ*mₕ*. The system is stable for all values of σ. For the exciton negative ion the calculations are carried out in terms of δ=mₕ*mₑ*. The existence of such a complex is highly improbable in the known semiconductors. The stability of the excited states for the exciton---ionized-donor complex has been studied qualitatively in CdS, CuCl, and CuBr. Reasonable agreement with experiment has been found for CdS.