Pressure Dependence of the Raman Modes Related to the Phase Transitions in Cyclohexane

The pressure dependence of the Raman frequencies for the $ν_{21}$ mode is studied by using the volume data at room temperature close to the transitions among the phases of III, IV and V in cyclohexane. By determining the pressure dependence of the mode Grüneisen parameter $γ_{T}$ in the phases and taking the average values, the Raman frequencies of those modes associated with the phase transitions are predicted through the volume data in cyclohexane. Our predicted Raman frequencies agree with those observed experimentally in this organic molecule. The Raman frequencies of the other modes can be calculated in cyclohexane and also in some molecular crystals using the method given here.