The temperature response of the silicalite-1 unit cell is investigated via X-ray diffraction experiments and lattice dynamics simulations, with the use of a newly proposed force-field. The numerical results are in very good agreement with present and literature data. Further analysis of the present data shows that the Rigid Unit Mode (RUM) mechanism that is proposed in the literature is the dominant mechanism of thermal contraction of the zeolite. In addition, the expansion of the silicalite-1 unit cell upon n-hexane sorption is investigated. Simulation results show that even though the discernible changes of the crystal dimensions upon heating or sorption may affect membrane-substrate mechanical interactions, they have a minimal effect on the overall sorption capacity.