Bound states of the Klein－Gordon and Dirac equations for potential V₀tanh²(r/d)

The exact bound state wavefunctions and energy equations of Klein－Gordon and Dirac equations are given with equal scalar and vector potential s(r)=v(r)=V(r)/2=V_0\tanh^2(r/d). The relation between the energy equation and that of relativistic harmonic is discussed.