Although we have shown that VSC leads to faster energy exchange between the a2" and e' modes, this acceleration could be due to enhancement of either pseudorotation or IVR. To qualitatively distinguish between the two processes, we can measure the vibrational anisotropy (32) associated with the cross peaks. IVR involves energy transfer between e' and a2" modes perpendicular to each other (Fig. ), while pseudorotation causes energy exchange between e' and a2" modes parallel to each other (Fig. ). Thus, the anisotropy should start from -0.2 and 0.4 for the former and latter , respectively. In general, both processes occur concurrently, and the initial anisotropy lies between these values.