SPC model of water

The simple point charge (SPC) model is an empirical model of water. The molecule is modelled as a rigid isosceles triangle, having charges situated on each of the three atoms. As well as Coulombic interactions, the molecules interact via long-range Lennard-Jones sites, situated on the oxygen atoms. The parameters are as follows:

parameter	value
$\sigma$	$3.166$Å
$ϵ$	$0.650$ kJ mol-1
$r_{\mathrm{O}\mathrm{H}}$	$1.000$Å
${\mathrm{\angle }}_{\mathrm{H}\mathrm{O}\mathrm{H}}$	$109.47^{\circ }$
$q_{\mathrm{O}}$	$-0.82e$
$q_{\mathrm{H}}$	$\left|q_{\mathrm{O}}\right|/2$ (charge neutrality)

The SPC model has a dipole moment of 2.27 D.

Surface tension

The surface tension has been studied for the SPC model by Vega and Miguel.

Related models

Over the years a number of variants of the SPC model have been published:

• SPC/ε
• SPC/A
• SPC/E
• SPC/F
• SPC/F2
• SPC/FP
• SPC/FQ
• SPC/Fw
• SPC/HW
• SPC/L
• SPCP
• SPC-pol