The six dimensional potential energy surface of the ground state X (1)Sigma(+) of CCNN has been generated by the CCSD(T) approach. The quartic force field in dimensionless normal coordinates has been evaluated. This force field has been used to calculate a set of spectroscopic constants. The lowest singlet states are also investigated. The bound ground state has a potential energy barrier to dissociation due to an avoided crossing with the excited d (1)Sigma(+) state. The other singlet states are found to be repulsive with respect to the dissociation into C-2 and N-2.