TIP4P model of water

The TIP4P model is a rigid planar four-site interaction potential for water, having a similar geometry to the Bernal and Fowler model, which was proposed in 1933.

Parameters

The TIP4P 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	3.154	78.0	0	0.52	-2q(H)	0.15

Phase diagram

The following is the phase diagram of the TIP4P model in the pressure-temperature plane (adapted from Fig. 11 of ).

Plastic crystal phases

Recent simulations have demonstrated the existence of plastic crystal phases for the TIP4P model .

Melting point

The melting point ice Ih-water at 1 bar is $232(4)~K$.

Shear viscosity

The shear viscosity for the TIP4P model is 0.494 mPa.s at 298 K and 1 bar (experimental value 0.896 mPa.s ).

Virial coefficients

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

See also

The following is a list of empirical models that build upon this TIP4P model:

• TIP4F
• TIP4P
• TIP4P/2005
• TIP4P-Ew
• TIP4P/FQ
• TIP4P-HB
• TIP4P/Ice
• TIP4P-pol
• TIP4PQ/2005
• TIP4P-QDP
• TIP4P-QDP-LJ