When deformed beyond their elastic limits, crystalline solids flow plastically via particle rearrangements localized around structural defects. Disordered solids also flow, but without obvious structural defects. We link structure to plasticity in disordered solids via a microscopic structural quantity, “softness,” designed by machine learning to be maximally predictive of rearrangements. Experimental results and computations enabled us to measure the spatial correlations and strain response of softness, as well as two measures of plasticity: the size of rearrangements and the yield strain. All four quantities maintained remarkable commonality in their values for disordered packings of objects ranging from atoms to grains, spanning seven orders of magnitude in diameter and 13 orders of magnitude in elastic modulus. These commonalities link the spatial correlations and strain response of softness to rearrangement size and yield strain, respectively.

Adsorption microcalorimetry of small molecules such as CO 2 , CH 4 , O 2 and NH 3 was studied on three commercially available metal-organic frameworks (MOFs), namely: Basolite TM A100, Basolite TM C300 and Basolite TM F300. All studies were conducted by interfacing a volumetric adsorption apparatus, Micromeritics ASAP 2020, with a differential scanning calorimeter, which runs isothermally. The CO 2 adsorption studies were performed on A100 and C300, at four different temperatures, and the uptakes increased with rise in temperature with significantly higher uptakes (approximately double) observed on C300. The differential heats on the A100 sample were confined in a low range of 18-36 kJ mol -1 and appeared to have similar profiles irrespective of the temperature. Comparably, low differential heats in the range of 21-27 kJ mol -1 were also observed for CO 2 adsorption on C300. However, unlike in A100, these heat profiles appeared to be relatively discrete and tend to decrease with increasing temperature. Adsorption of CH 4 on A100 showed increase in uptakes with temperature and very similar heats of adsorption profiles (16.5-19.5 kJ mol -1 ). O 2 adsorption studies on C300 indicated an increase in uptakes with temperature and scattered heat values (11.5-16.5 kJ mol -1 ) at all temperatures. NH 3 adsorption on F300 at 40°C using the ''two-isotherm'' method yielded an irreversible uptake of *4 mmol g -1 and an initial heat of 102 kJ mol -1 . Overall, it appears that MOFs have appreciable amount of adsorption capacity for small molecule adsorbates within a very low range of adsorption heats.