SPC/E model of water

The extended simple point charge model, SPC/E is a slight reparameterisation of the SPC model of water, with a modified value for $q_{\mathrm {O} }$ . The molecule is modelled as a rigid isosceles triangle, having charges situated on each of the three atoms. Apart from Coulombic interactions, the molecules interact via long-range Lennard-Jones sites, situated on the oxygen atoms. The parameters are as follows:

parameter	value
$\sigma$	$3.166{\mathrm {\AA} }$
$\epsilon$	$0.650$ kJ mol^-1
$r_{\mathrm {OH} }$	$1.000\mathrm {\AA}$
$\angle _{\mathrm {HOH} }$	$109.47^{\circ }$
$q_{\mathrm {O} }$	$-0.8476e$
$q_{\mathrm {H} }$	$q_{\mathrm {O} }/2$ (charge neutrality)