Figure 3: Bond auto-correlation functions (BACF) of H₂O, CH₄, mixture of H₂O–CH₄ and SU.

(a) BACF for four type of bond: C–C (black), C–N (blue), C–O (green) and C–H (red) for different temperatures (1,837 K: solid lines green shading, 4,000 K: dashed lines grey shading and 7,260 K: dotted lines orange shading) at a density of 3 g cm⁻³ (this corresponds to a pressures of 160, 176 and 200 GPa, respectively); (b) A snapshot of the molecular dynamics simulation at a density of 3 g cm⁻³ at 4,000 K. This corresponds to the reticulating phase. Carbon atoms are light blue, oxygens are red, nitrogens are blue and hydrogens have been masked to highlight the scale of the carbon network; (c) BACF of different mixtures at 4,000 K and 176 GPa. Black denote C–C bonds, green denote C–O bonds and red denote C–H bonds. The solid lines represent the synthetic Uranus, the dashed line represent a water–methane mixture and the dot dashed line represents pure methane.