Difference between revisions of "Weeks-Chandler-Andersen perturbation theory"

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(New page: The '''Weeks-Chandler-Anderson perturbation theory''' is based on the following decomposition of the intermolecular pair potential (in particular, the [[Lennard-Jones model | Lennard-J...)
 
m
Line 5: Line 5:
  
 
:<math>
 
:<math>
u_{\rm repulsive} (r) = \left\{  
+
\Phi_{\rm repulsive} (r) = \left\{  
 
\begin{array}{ll}
 
\begin{array}{ll}
 
u_{\rm LJ}(r) + \epsilon & {\rm if} \; r < 2^{1/6}\sigma \\
 
u_{\rm LJ}(r) + \epsilon & {\rm if} \; r < 2^{1/6}\sigma \\
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:<math>
 
:<math>
u_{\rm attractive} (r) = \left\{  
+
\Phi_{\rm attractive} (r) = \left\{  
 
\begin{array}{ll}
 
\begin{array}{ll}
 
-\epsilon & {\rm if} \; r < 2^{1/6}\sigma \\
 
-\epsilon & {\rm if} \; r < 2^{1/6}\sigma \\

Revision as of 15:16, 21 June 2007

The Weeks-Chandler-Anderson perturbation theory is based on the following decomposition of the intermolecular pair potential (in particular, the Lennard-Jones potential ):

The reference system pair potential is given by (Eq, 4 Ref. 1):


\Phi_{\rm repulsive} (r) = \left\{ 
\begin{array}{ll}
u_{\rm LJ}(r) + \epsilon & {\rm if} \; r < 2^{1/6}\sigma \\
0 &  {\rm if} \; r \ge 2^{1/6}\sigma 
\end{array} \right.

and the perturbation potential is given by (Eq, 5 Ref. 1):


\Phi_{\rm attractive} (r) = \left\{ 
\begin{array}{ll}
-\epsilon & {\rm if} \; r < 2^{1/6}\sigma \\
u_{\rm LJ}(r) &  {\rm if} \; r \ge 2^{1/6}\sigma 
\end{array} \right.

References

  1. John D. Weeks, David Chandler and Hans C. Andersen "Role of Repulsive Forces in Determining the Equilibrium Structure of Simple Liquids", Journal of Chemical Physics 54 pp. 5237-5247 (1971)