Thermodynamic behavior of a water model with a liquid–liquid critical point

In this paper we calculate the constant pressure specific heat response of a water model with a liquid–liquid critical point. We show how, due to the existence of the critical point, there is a secondary maximum in the specific heat at some temperature T*>Th for any pressure P>Pc, being Th the first order transition temperature between the high and the low density liquid phases and Pc the pressure of the critical point. This secondary maximum does not correspond to any long range correlated phase transition and does not show up in the temperature dependence of the isothermal compressibility.