The [Lennard-Jones potential][1] describes long-range attraction and short-range repulsion. In both solids, liquids, and gases there are attractions and repulsions. 

1. *Does it mean that Lennard-Jones form of potential is applicable to any phase of a substance?*

2. *If yes, does the attractive and repulsive parts of the potential have the same origin in all phases?*


  [1]: https://en.wikipedia.org/wiki/Lennard-Jones_potential