We must have substituted the mass m in the hydrogen formulae with the decreased mass to account for the motion of the nucleus. Positronium is an electrically bound system of an electron and a positron. By using the suitable reduced mass:
i) Compute the energies of the n = 1 and n = 2 states of positronium.
ii) Compute separately the relativistic mass correction and the spin-orbit energy shifts for positronium. Please put your energies in eV.