Ramp model: Difference between revisions

From SklogWiki
Jump to navigation Jump to search
mNo edit summary
m (Better defined r)
Line 2: Line 2:


:<math>
:<math>
\Phi(r) = \left\{  
\Phi_{12}(r) = \left\{  
\begin{array}{ll}
\begin{array}{ll}
\infty & {\rm if} \; r < \sigma \\
\infty & {\rm if} \; r < \sigma \\
Line 11: Line 11:
</math>
</math>


where <math>\Phi(r)</math> is the [[intermolecular pair potential]], <math>W_r > 0</math> and <math>W_a < 0</math>.
where <math>\Phi_{12}(r)</math> is the [[intermolecular pair potential]], <math>r := |\mathbf{r}_1 - \mathbf{r}_2|</math>, <math>W_r > 0</math> and <math>W_a < 0</math>.


Graphically, one has:
Graphically, one has:

Revision as of 14:58, 17 July 2008

The ramp model, proposed by Jagla, is described by:

where is the intermolecular pair potential, , and .

Graphically, one has:

where the red line represents an attractive implementation of the model, and the green line a repulsive implementation.

Critical points

The liquid-vapour critical point is located at (Ref. 4)

The liquid-liquid critical point is located at (Ref. 4)

See also

References

  1. E. A. Jagla "Core-softened potentials and the anomalous properties of water", Journal of Chemical Physics' 111, pp. 8980-8986 (1999)
  2. E. Lomba, N. G. Almarza, C. Martin, C. McBride "Phase behaviour of attractive and repulsive ramp fluids: integral equation and computer simulation studies", Journal of Chemical Physics 126 244510 (2007)