~~NOTOC~~
====== Examples : Pair Potentials ======

----

<wrap round important 560px center>
//**Warning:**//
This is an example potential. Please do NOT use it for any real simulations!
</wrap>

This is a simple pair potential that can be used in //potfit//. 
The analytic function used is a Lennard-Jones.

It makes use of the **global parameters** feature.

<code potfit Example_Pair_2>
#F 0 3
#T PAIR
#I 0 0 0
#E

# This is the definition of 1 global parameter called epsilon
global 1
epsilon 0.10    0.00    1.00

type lj
cutoff 6.0
# Use the global parameter epsilon
epsilon!
sigma   2.50    1.00    4.00

type lj
cutoff 6.0
# Use the global parameter epsilon
epsilon!
sigma   2.50    1.00    4.00

type lj
cutoff 6.0
epsilon 0.10    0.00    1.00
sigma   2.50    1.00    4.00
</code>

The first parameter of the first two lj-potentials (epsilon!) will be replaced with the epsilon
parameter of the global section. This can be used to share parameters amongst several potentials.

==== makeapot ====

The example potential can be generated with the following ''makeapot'' command:

<WRAP round tip>
//**Hint:**//
Global parameters are not supported by makeapot. They have to be introduced manually in
the potential file. The plain potential file can be generated with
</WRAP>

  makeapot -n 2 -i pair -f 3*lj