Fig. 4: Energy vs. volume curves for three pressure-induced transformations.

a SnC, b BaTe, and c Ti₃O₄. The zero-pressure stable phases are colored blue, and the high-pressure stable phases are colored orange. Differences between the two phases in terms of zero-pressure volume (∆V₀), zero-pressure bulk modulus (∆B), and zero-pressure energy (∆E₀) are listed in the plots. The vertical lines and horizontal lines indicate V₀ and E₀, respectively. The Materials Project (MP) material IDs of the phases are provided in the labels of the curves. a, b show phase transformation because the high-pressure phase is denser, and c shows phase transformation because the high-pressure phase is softer.