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examples:potentials:pair:2

# Examples : Pair Potentials

Warning: This is an example potential. Please do NOT use it for any real simulations!

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.

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

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:

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

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