Fig. 2
From: Giant barocaloric effects over a wide temperature range in superionic conductor AgI
First-principles calculations of AgI polymorph entropy. For the a β and b γ polymorphs in the β + γ phase, we show phonon dispersion spectra at the equilibrium volume (solid black and red), and on reducing the volume by 2% (dashed blue) (ω denotes the angular frequency of vibration on passing between the labelled points of the Brillouin Zone). c Vibrational entropy S for the β (black) and γ (red) polymorphs at 400 K, normalized by formula unit (f.u., left axis) and mass (right axis). Experimentally, a pressure of 1.25 kbar drives the transition at 400 K (vertical blue line)
