Fig. 7: Energy-volume relations (and fit to the Murnaghan equation of state, Equation (15)) from isotropic compression and expansion of nine fully relaxed snapshots from the 600 K-NPT CP molecular dynamics of t-LGPS, and of the global minimum energy structure reported in ref. 78, previously fully relaxed.
From: Solids that are also liquids: elastic tensors of superionic materials

At each volume the energy is calculated by relaxing the atoms (see main text).