TIP4PQ/2005 model of water

The TIP4PQ/2005 model is a re-parameterisation of the TIP4P/2005 potential for quantum path integral simulations of water, in particular for the ice phases. The difference between the TIP4P/2005 and the TIP4PQ/2005 models is the dipole moment, which increases from 2.305D to 2.38D thanks to the difference in the charges: TIP4P/2005 q(H) (e) is 0.5564 whereas for the TIP4PQ/2005 model this becomes 0.5764e.

Parameters

$r_{\mathrm {OH} }$ (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	0.5764	-2q(H)	0.1546

Phase diagram

The phase diagram of the TIP4PQ/2005 model in the pressure-temperature plane (adapted from Fig. 3 of )

Density maximum

The TIP4PQ/2005 model has a density maximum in the liquid phase at 280K .

References

Related reading

• C. Vega, M. M. Conde, C. McBride, J. L. F. Abascal, E. G. Noya, R. Ramirez, and L. M. Sesé "Heat capacity of water: A signature of nuclear quantum effects", Journal of Chemical Physics 132 046101 (2010)
• Briesta S. González, Eva G. Noya, Carlos Vega and Luis M. Sesé "Nuclear Quantum Effects in Water Clusters: The Role of the Molecular Flexibility", Journal of Physical Chemistry B (Article ASAP) (2010)