Quasilinearity in tetratomic molecules: An ab initio study of the CHNO family

Abstract : We present coupled-cluster CCSD(T) all electron results for the equilibrium structure of isofulminic acid, HONC, together with results for the barrier to linearity and the energetics for the four most stable members of the CHNO isomer family, obtained for the ground electronic states by means of large correlation consistent basis sets. Minimum energy paths along the angular coordinates reported for these CHNO isomers are combined with the dominant kinetic energy contributions to predict key rovibrational spectroscopic features which are clearly reminiscent of quasilinear behavior in tetratomic molecules.