The interaction potential for the ground and A Rydberg state of NO-H-2 has been calculated using high level ab initio methods. The complex is very floppy in nature and large amplitude motions are expected to characterize its dynamics. The ground state is characterized by two very close-lying states which exhibit crossings. By analogy with other complexes the Rydberg state is characterized by much smaller well depth and larger intermolecular distance. We compare with model potential's used in previous molecular dynamics simulations of photoexcitation and relaxation and conclude on the importance of performing new studies. (C) 2016 Elsevier B.V. All rights reserved.