The contribution to the entropy by each set of degrees of freedom in internal thermodynamic equilibrium tends to zero in a differentiable way as the absolute zero of temperature is approached. The lim...The contribution to the entropy by each set of degrees of freedom in internal thermodynamic equilibrium tends to zero in a differentiable way as the absolute zero of temperature is approached. The limiting value of S is independent of the process by which T=0 is approached; it does not matter whether the system is in liquid or solid phase, whether it is under pressure, etc.