This work gives a full account of the N(⁴S/²D)+${\mathrm{N}}_2\left({}^1\Sigma _g^{+}\right)$ interactions via accurate electronic structure calculations and study of the involved exchange reactions. A 2 × 2 diabatic representation of the potential energy surface is suggested for N₃(²A^′), which, combined with the two previously reported adiabatic forms for ²A^″ and another for ⁴A^″, completes the set of five global potentials required to study the title collisional processes. The trajectory results provide the first N(²D)+N₂ rate constants, and allow a comparison with the ones for N(⁴S)+N₂. Nonadiabatic effects are estimated by surface hopping, and the geometrical phase effect assessed by following the trajectories that encircle the crossing seam.