An ab initio study of the structure, vibrational frequencies and heat of formation of ONCO radical

The structure, infrared vibrational frequencies, and heat of formation of ONCO radical were calculated using ab initio molecular orbital theory. Calculations were performed using various basis sets in conjunction with various post-Hartree-Fock methods. The most elaborate optimized geometry was calculated using quadratic configuration interaction theory with perturbative correction for the triples (QCISD(T)) with the 6–311G(2d, 2p) basis set. At this level of theory the structure is bound with an N-C bond length of 1.283 Å. Using G2 theory the heat of formation of ONCO radical is 20.2 kcal mol−.