Cooling of the sample post-pumping occurred primarily through radial conduction into the unpumped region of the zeolite pellet. Examination of the effects of cooling into the surrounding air (ESI Section 12) found the contribution of these processes to be minimal. The dominating parameters affecting the rate of radial cooling within the simulation were found to be the pump and probe spot sizes and the thermal conductivity of the zeolite, κ. While the spot size was well characterised by experimental measurements (ESI Section 3) it was not possible to determine a reasonable estimate for the value of κ from the literature. A range of reasonable values were determined empirically by finding the range of κ values for which the fitted time constants fell within the confidence intervals of the experimental cooling curve, with each of the other simulation parameters allowed to vary within their own confidence intervals. This gave a value of κ = 0.25 ± 0.1 W m -1 K -1 for simulations with TInit from 125-300 °C. The predicted value of κ increases with temperature which is consistent with the results obtained for measurements of thin films, although the κ values determined from our experiments are approximately 4 times smaller, possibly indicating the much lower level of thermal contact between crystallites than in a pure film. It was not possible to derive a value for the thermal conductivity that produced cooling behaviour consistent with the experimental observations at 80 and 100 °C, indicating that at these temperatures there are additional effects that the simulations do not account for. This results in a deviation of the experimental and simulated T-jump results at low temperatures, which is considered in more detail below. The derived values for κ are given in Table in the ESI (Section 9). The analysis approximates the thermal conductivity as constant during the heating and cooling process.