q-TIP4P/F model of water

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The q-TIP4P/F model [1] is a flexible version of the TIP4P/2005 model of water designed for use in path integral simulations.

Melting point[edit]

The melting point was found to be 251 \pm 1.5~K at 1 bar via direct coexistence calculations, and at 257K from calculations of the Gibbs energy function [2].

Isotope effects[edit]

Melting point (extract from the Ice Ih page)

T_m (D20) Pressure Water model/technique Reference
257.5(5)~K 1 bar q-TIP4P/F [3]
276.83 \pm 0.02 K 1 bar experimental value [4]
T_m (T20) Pressure Water model/technique Reference
259.2(5)~K 1 bar q-TIP4P/F [3]
277.64  K 0.6629 kPa experimental value [5]

It is worth pointing out that the calculations presented in the work of Ramírez and Herrero [3] used the melting point of the q-TIP4P/F model as its "reference state". It is perhaps more fruitful to examine the relative changes upon isotopic substitution: \Delta T_m (D_2O - H_2 0) = 6.5 K (experimental value: 3.68 K) and \Delta T_m (T_2O - H_2 0) = 8.2 K (experimental value: 4.49 K).

Ice Ih[edit]

Isotope effects have also been studied for ice Ih [6].