Phase transition and chemical decomposition of liquid carbon dioxide and nitrogen mixture under extreme conditions

Thermodynamic and chemical properties of liquid carbon dioxide and nitrogen (CO₂-N₂) mixture under the conditions of extremely high densities and temperatures are studied by using quantum molecular dynamic (QMD) simulations based on density functional theory including dispersion corrections (DFT-D). We present equilibrium properties of liquid mixture for 112 separate density and temperature points, by selecting densities ranging from ρ =1.80 g/cm³to 3.40 g/cm³ and temperatures from T=500 K to 8000 K. In the range of our study, the liquid CO₂-N₂ mixture undergoes a continuous transition from molecular to atomic fluid state and liquid polymerization inferred from pair correlation functions (PCFs) and the distribution of various molecular components. The insulator-metal transition is demonstrated by means of the electronic density of states (DOS).