From: Jérôme Hénin (
Date: Mon Nov 23 2015 - 03:33:30 CST


This is not a VMD (or a NAMD) question. This is a basic math / phys chem

Look at the graph of a Lennard-Jones potential, and you'll see the answer
to your question. If you don't, take a math class.


On 23 November 2015 at 03:15, sunyeping <> wrote:

> Dear all,
> When calculating the interaction energy between two groups of residues
> with Namd Energy Plugin in VMD, I find the the value of the interaction
> energy is negative but that of the force is positve. According to the user
> guide of the Namd Energy plugin (
>, a positive
> force is repulsive. But does the negative value of the interaction energy
> suggest a favorable binding? So whether are these two groups of residues
> attractive or repulsive?
> Thanks in advance.
> Yeping Sun
> Institute of Microbiology, Chinese Academy of Sciences