The molecular parameters of fluorofulminate, FCNO, have been predicted in ab initio calculations using the coupled-cluster method, CCSD(T), and basis sets of double- through quadruple-zeta quality. In contrast to other halofulminates (CICNO and BrCNO), the equilibrium structure of the FCNO molecule was found to be well bent, with the parameters r(e)(FC) = 1.301 Angstrom, r(e)(CN) = 1.200 Angstrom, r(e)(NO) = 1. 199 Angstrom, angle(e)(FCN) = 135.1degrees, and angle(e)(CNO) = 162.0degrees. The height of a barrier to linearity of the FCNO chain was predicted to be 1870 cm(-1). The harmonic frequencies and, in particular, FCN bending-rotation energy levels were calculated. To assist in a future analysis of the high-resolution spectra of fluorofulminate, the effective rotational constant B-v was,predicted for various states of the FCN bending mode. The determined regular pattern of low-lying energy levels is consistent with that characteristic of a semirigid bent molecule with a moderately anharmonic bending potential energy function.