Quantum-chemical calculations on isomers of C5O

For C5O as five structural isomers we calculated the properties energy, geometry, vibrational wavenumbers, infrared intensities, rotational parameters and dipole moment with density functionals of two types - B3LYP and PW91PW91. We applied time-dependent density functional theory to calculate the energies and oscillator strengths of electronic transitions for these isomers. These data might assist an identification of these species in the laboratory and in space.