Spectroscopy: IR/Raman: Normal modes of vibration of 5-Nonanone

All these geometries and frequencies were theoretically calculated at the DFT-B3LYP level of theory (6-31+G(d,p) basis sets for light atoms and Stuttgart ECPs for the heaviest ones; an empirical harmonic vibrational frequency scale factor of 0.94 has systematically been applied to theoretical frequencies

More information about infrared spectroscopy on Wikipedia. In relation with the IR or Raman activity of a mode, see also the character tables for the more common molecular point groups.