[gmx-users] why are the values of the LJ interaction energy negative and the values of the Coulomb interaction energy positive between two group.

[Mark Abraham]

Jinyao Wang wrote:
> Hi gmx-users,
>    I have calculated the interaction energy between two group. But I find that the values of the LJ interaction energy are negative and the values of the Coulomb interaction energy are positive between two group. So I think the LJ interaction is attractive and the Coulomb interaction is repulsive. Is it correct for my consideration of the interaction ?  

Maybe. That conclusion would assume
a) that you've calculated it correctly,
b) that the model physics is robust with respect to such a decomposition
when it almost certainly wasn't parameterized for such a property, and
c) the decomposed interaction energy means anything.

Mark