The triple point of ${\mathrm{CO}}_2$ occurs at 5.1atm and $-{56}^{\circ }C$. Its critical temperature is ${31}^{\circ }C$. Solid ${\mathrm{CO}}_2$ is more dense than liquid ${\mathrm{CO}}_2$. Under which combination of pressure and temperature is liquid ${\mathrm{CO}}_2$ stable at equilibrium?

At pressures less than 5.11177 atm, carbon dioxide has no liquid state. At 1 atm (0.101325 MPa), the gas deposits immediately to a solid below 194.6855(30) K and the solid sublimes directly to a gas above this temperature.