Van der Waals force (Lenard-Jones)

[Ferra]

Hi everyone

I'd like to know the Lennard-Jones potential energy is just for symmetric particles or we can use it for asymmetric forces too? If not how can I define the potential energy between two asymmetric particles?

Thanks

 

[DrClaude]

The Lennard-Jones potential is a central potential, and therefore assumes spherical particles. I guess it could be modified such that the parameters of the potenial depend on the relative orientation of the two particles. I am not aware if this has been done before.

 

[Ferra]

Thank you so much for your information. Actually except the orientation I'd like to know if the size of the particles also cause the interaction potential energy to be asymmetric or not?

 

[DrClaude]

I don't understand. Asymmetric with respect to what?

 

[Ferra]

For example for two cylindrical particles with different length this interaction energy is symmetric or the longer one has more influence on the shorter one?