A three-dimensional ab initio potential energy surface of the Kr–N 2 O complex was calculated using the CCSD(T) method and avqz-pp+33221 basis set. The potential includes explicit dependence on the v 3 stretching coordinate of the N 2 O molecule. The potential energy surface is characterized by a near T-shaped minimum. The global minimum locates at R=6.70a 0 and θ=96.00° with a depth of −270.29cm −1 . Using the fitted potential energy surface, we have calculated bound energy levels of the Kr–N 2 O complexes. The resulting the potential provides a good representation of the experimental data.