The ν3 band of CD3CD3: High resolution stimulated Raman spectrum and global three band analysis

Stimulated Raman spectroscopy has been used to study rotationally resolved Q-branch of the ν3 band. This spectrum is analyzed with data from the ν9 fundamental, ν9 + ν4 − ν4 hot band and transitions from ν4 and 3ν4 torsional bands. One torsional component of the ν3 fundamental is near degenerate with its interacting partner v4 = 5 of the ground state torsional bath. The coupling was modeled using a Fermi-type interaction. The introduction of the Fermi-type interaction causes a large change in the barrier height for the ground vibrational state and makes the barrier shape parameter redundant, indicating the vibrational contributions to the experimental barrier shape are dominant.