SPC model of water

The simple point charge (SPC) model ^[1] 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
$\epsilon$	$0.650$ kJ mol^-1
$r_{\mathrm {OH} }$	$1.000$ Å
$\angle _{\mathrm {HOH} }$	$109.47^{\circ }$
$q_{\mathrm {O} }$	$-0.82e$
$q_{\mathrm {H} }$	$\|q_{\mathrm {O} }\|/2$ (charge neutrality)