TIP4P/2005 model of water

The TIP4P/2005 model is a re-parameterisation of the original TIP4P potential for simulations of water. TIP4P/2005 is a rigid planar model, having a similar geometry to that of the Bernal and Fowler model.

Parameters

The TIP4P/2005 model consists of a Lennard-Jones site for the oxygen atom, and three charge sites.

$r_{\mathrm {OH} }$ (Å)	$\angle$HOH , deg	$\sigma$ (Å)	$\epsilon /k$ (K)	q(O) (e)	q(H) (e)	q(M) (e)	$r_{\mathrm {OM} }$ (Å)
0.9572	104.52	3.1589	93.2	0	0.5564	-2q(H)	0.1546

• DL_POLY FIELD file for the TIP4P/2005 model
• GROMACS files for the TIP4P/2005 model
• NAMD files for the TIP4P/2005 model

Phase diagram

The phase diagram of the TIP4P/2005 model in the pressure-temperature plane (adapted from Fig. 9a of ) is given in a publication by Abascal, Sanz and Vega

and for negative pressures in the publication

Plastic crystal phases

Recent simulations have suggested the possibility of a plastic crystal phase or phases for water

Supercooled region

The supercooled region has been studied by Abascal and Vega , locating a Widom line , indicating a second critical point for water located at 1350 bar and 193 K.

Surface tension

The surface tension has been studied for the TIP4P/2005 model, giving $\gamma =69.1$ mJ/m² at 300 K using the test area method , $\gamma =68.4$ mN/m at 300 K using using the Ewald sums for the dispersion interactions , $\gamma =59$ mJ/m² at 350 K using the reaction field method and $\gamma =74.8$ mN/m at 249 K .

Self-diffusion coefficient

The TIP4P/2005 potential has a self-diffusion coefficient, in bulk water at 298 K, of 0.21 Ų ps⁻¹ in a classical simulation of 216 water molecules (experimental value: 0.23 Ų ps⁻¹) . See also .

Shear viscosity

The shear viscosity for the TIP4P/2005 model is 0.855 mPa.s at 298 K and 1 bar (experimental value 0.896 mPa.s ).

Liquid-liquid critical point

For the TIP4P/2005 model the liquid-liquid critical point is located at $T_{c}=193$K, $p_{c}=1350$ bar and having a density of $\rho _{c}=1.012$ g/cm³ .

Structure factor

The structure factor, in particular for small wave vectors, has been calculated by Sedlmeier, Horinek and Netz , who observe that the TIP4P/2005 model yields an "almost quantitative agreement".

Virial coefficients

The second virial coefficient has been calculated by Chialvo et al .

Thermal conductivity

Thermal conductivity .

References

Related reading

• Helena L. Pi, Juan L. Aragones, Carlos Vega, Eva G. Noya, Jose L. F. Abascal, Miguel A. Gonzalez and Carl McBride "Anomalies in water as obtained from computer simulations of the TIP4P/2005 model: density maxima, and density, isothermal compressibility and heat capacity minima", Molecular Physics 107 pp. 365-374 (2009)

External links and resources

• Presentation: Comparing the performance of TIP4P/2005 with other water models