  Solid-state refrigeration technology based on caloric effects are promising
to replace the currently used vapor compression cycles. However, their
application is restricted due to limited performances of caloric materials.
Here, we have identified colossal barocaloric effects (CBCEs) in a class of
disordered solids called plastic crystals. The obtained entropy changes are
about 380 J kg-1 K-1 in the representative neopentylglycol around room
temperature. Inelastic neutron scattering reveals that the CBCEs in plastic
crystals are attributed to the combination of the vast molecular orientational
disorder, giant compressibility, and high anharmonic lattice dynamics. Our
study establishes the microscopic scenario for CBCEs in plastic crystals and
paves a new route to the next-generation solid-state refrigeration technology.
