Adiabatic potential energies as a function of internuclear distance R for the lowest ten states of the NaH quasi-molecule from pseudo-potential calculations by Dickinson et al. (1999). The atomic states and energies at dissociation are shown at the right-hand side of the figure. The thick, dashed (red) line shows the 1/R interaction corresponding to the interaction for the pure ionic configuration Na⁺+H⁻ at long range.