Fig. 3.

Results for the TIP5P potential. (a) Relevant part of the phase diagram, showing the liquid–liquid critical point C at P_c ≈ 320 MPa and T_c ≈ 217 K, the line of isobaric specific heat maxima , and the line of isothermal compressibility maxima .(b) Arrhenius plot of the diffusion constant D as a function of 1,000/T along different isobars. The filled circles indicate the temperatures at which the line is crossed. (c) Arrhenius plot of D as a function of 1,000/T for P = 100 MPa (path α). At high temperatures, D can be fit by D ∼ (T – T_MCT)^γ (dashed line, also shown in Inset), where T_MCT ≈ 231 K and γ ≈ 1.9. At low temperatures, the dynamic behavior changes to that of a liquid where D is Arrhenius (solid line). (d) Log–log plot of D as a function of T – T_MCT for P = 400 MPa (path β). The behavior of D remains non-Arrhenius for the entire temperature range and is consistent with D ∼ (T – T_MCT)^γ, with T_MCT ≈ 201 K and γ ≈ 2.5. Note that the power law fits for γ and T_MCT are subject to error due to the relatively small ranges of D and T – T_MCT.