Hybrid two-dimensional (2D) Raman-THz spectroscopy is a novel spectroscopic technique to study coupling between low-frequency molecular motions in the THz frequency region (0.1-10 THz) [1]. Recently, we demonstrated that this technique can be used to observe vibrational couplings between sharp intramolecular and broad intermolecular vibrational modes in liquid CHBr₃ and binary CHBr₃-MeOH mixture [2, 3]. In this work [4], 2D Raman-THz spectroscopy is used to study the crystalline β-phase of CHBr₃, expanding the applicability of this technique to solid samples at cryogenic temperatures. Moreover, this study elucidates the mechanism responsible for the observed cross peak features by providing new experimental evidence for anharmonic couplings between intra-/intermolecular vibrational modes. Finally, significant change in the spectral shape of the cross peaks upon the phase transition from liquid CHBr₃ to β-CHBr₃, in agreement with the corresponding THz absorption spectra, strongly supports our interpretation, and excludes the possibility of instantaneous interactions of THz field with intramolecular modes.