On p. 3275 ff. C. A. Fernandez, P. K. Thallapally et al. present a study on the carbon-dioxide-induced expansion and contraction of the porous lattice in a partially fluorinated metalorganic framework as a function of temperature. The results indicate that two structural transitions take place during CO2 adsorption. The first one (at low CO2 pressures) corresponds to shrinkage of the framework while, at relatively high CO2 pressures, a framework expansion takes place, as evidenced by a large hysteresis loop in the adsorption/desorption isotherms and an associated energy cost.