# TIP4PQ/2005 model of water

The **TIP4PQ/2005** model
^{[1]}
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[edit]

(Å) | HOH , deg | (Å) | (K) | q(O) (e) | q(H) (e) | q(M) (e) | (Å) |

0.9572 | 104.52 | 3.1589 | 93.2 | 0 | 0.5764 | -2q(H) | 0.1546 |

## Phase diagram[edit]

The phase diagram of the TIP4PQ/2005 model in the pressure-temperature plane (adapted from Fig. 3 of ^{[2]})

## Density maximum[edit]

The TIP4PQ/2005 model has a density maximum in the liquid phase at 280K ^{[3]}.

## References[edit]

- ↑ Carl McBride, Carlos Vega, Eva G. Noya, Rafael Ramirez, Luis M. Sese "Quantum contributions in the ice phases: the path to a new empirical model for water -- TIP4PQ/2005", Journal of Chemical Physics
**131**024506 (2009) - ↑ Carl McBride, Eva G. Noya, Juan L. Aragones, Maria M. Conde and Carlos Vega "The phase diagram of water from quantum simulations", Physical Chemistry Chemical Physics
**14**pp. 10140-10146 (2012) - ↑ E. G. Noya, C. Vega, L. M. Sesé, and R. Ramírez "Quantum effects on the maximum in density of water as described by the TIP4PQ/2005 model", Journal of Chemical Physics
**131**124518 (2009)

**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)