The geometry and harmonic vibrational frequencies of the the (C) over tilde (2)A(2) electronic state of nitrogen dioxide have been determined using coupled cluster (CC) theory in conjunction with large basis sets. The minimum energy C-2v-constrained N-O bond distance predicted by the highest level of theory is significantly shorter than the experimentally inferred value, and it is unlikely that further refinement in the theoretical treatment would reduce the discrepancy. However, this work suggests that a prevailing assumption of C-2v symmetry may be incorrect; the equilibrium structure of the (C) over tilde state may instead have C-s symmetry. In addition, and contrary to expectation, CC calculations based on variationally optimal spin-unrestricted or spin-restricted reference determinants give qualitatively different results for this system, unless very high levels of electron correlation are included in the calculation.