The organic-inorganic perovskites (CH3NH3Pb(Br,Cl,I)3) have been identified as efficient photovoltaic materials. Theoretical calculations have suggested that the low energy lattice fluctuations influence the band structure and neutron results on powders have indeed shown a coupling between the organic molecule and the inorganic framework. We propose to investigate the molecular dynamics in CH3NH3PbCl3 and plan to compare these with our previous measurements on the Br variant (performed on IRIS). These measurements will also be related to current triple-axis studies on single crystals of the Pb based framework. The entire proposal requests 4 days on IRIS.