Editing SPC/HW model of water

The '''SPC/HW''' model is an [[SPC]] model designed for heavy [[water]]. 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 model | Lennard-Jones]] sites, situated  on the  oxygen atoms, i.e. (Ref. 1 Eq. 1):

:<math>\Phi_{i,j}= \left[ \frac{C_{12}}{r_{OO}(i,j)}\right]^{12} - \left[ \frac{C_{6}}{r_{OO}(i,j)}\right]^{6} + \sum_{\alpha=1}^3 \sum_{\beta=1}^3 \frac{q_\alpha(i) q_\beta(j)}{r_{\alpha \beta}(i,j)}</math>

The parameters are as follows (Ref 1 Table I. Note, in the table the HOH (DOD) angle is given as 109.43 but in the text as 109.47):
[[Image:Thee_site_water_model.png‎|center|400px]]
{| border="1"
|- 
| parameter || value
|-  
| <math>C_{12}</math> || <math> 0.3428 </math> (kJ mol<sup>-1</sup>) <sup>1/12</sup>nm
|-
| <math>C_6</math> || <math> 0.3712 </math> (kJ mol<sup>-1</sup>) <sup>1/6</sup>nm
|-
| <math>r_\mathrm{OH}</math> || <math>1.000\mathrm{\AA}</math>
|-
| <math>\angle_\mathrm{HOH}</math> || <math>109.47^{\circ}</math>
|-
| <math>q_{\mathrm{O}}</math> ||  <math>-0.87 e</math>
|-
| <math>q_{\mathrm{H}}</math> ||  <math>q_{\mathrm{O}}/2</math> (charge neutrality)
|}

==References==
#[http://dx.doi.org/10.1063/1.1359183 J. Raul Grigera "An effective pair potential for heavy water", Journal of Chemical Physics '''114''' pp. 8064-8067 (2001) ]
[[category: water]]
[[category: models]]