Absolute IR vibrational band intensities of hexafluoroacetone: Comparison of experiment and anharmonic ab initio calculation using the second-order operator canonical Van Vleck perturbation theory

•Absolute infrared intensities of fourteen fundamental bands of gaseous hexafluoroacetone were determined in the range of 2000–340 cm−1.•A theoretical ab initio anharmonic vibrational spectrum was calculated by means of operator canonical Van Vleck perturbation theory (CVPT).•Good correspondence was achieved between experimental and theoretical values of IR frequencies and absolute integral intensities.•The ν4, ν7, ν10 and ν15 fundamental bands were reassigned, and three predicted Fermi resonances were identified in experimental spectra.