Density effect on the Fermi resonance in gaseous CO2 by Raman scattering

Abstract
Raman scattering was used to study the Fermi resonance of ν1 and 2 ν2 bands in gaseous CO2 over the density interval of 15–534 amagat. Both vibrations were found to shift to lower frequency as density was increased. The resonance repulsion of the two bands was also found to increase with increasing density.