Fig. 5: Illustration of criterion parameters, cut off function, and phonon density of states (PDOS) spectra of H2O.
From: Colossal barocaloric effect in GdCl3-doped H2O for sustainable cooling
a Cut off function r(θ) = −0.00044θ2 + rmax with rmax ≈ 2.9 Å46. The shaded area denotes intact H-bonds and the other region represents broken ones. b Illustration of the (r, θ) between the two neighboring molecules defined in the simulation. The phonon density of states (PDOS) spectra of H2O in c ice and d water at 298 K. e Contribution from O atoms and f from H atoms in PDOS. Green dashed line in d and e indicates the imaginary frequency in the calculation results of liquid water. The PDOS is calculated within the harmonic approximation at 0 K, which eventually leads to the occurrence of an imaginary frequency in the disordered water.
