Herein, we use molecular simulation to investigate NTE for a representative collection of mesoporous MOFs, illustrated in Figure . These MOFs demonstrate record values of porosity, approaching 90% free volume, and encapsulate mesopores ranging between 23-43 Å, Table . Classical molecular simulation was employed to predict structural changes from 40-400 K and identify the origins for NTE in these materials. We also considered the intrinsic temperature-induced structural changes of the large molecular subunits that make up the frameworks and thus contribute to their NTE. Finally, the changes in mechanical properties originating from these pronounced structural deformations were computed to provide essential insight into the stability of these materials.