[ESPResSo-users] Tabulated angle potential in Espresso

[Hender Lopez]

Dear all,

I am trying to use a tabulated potential for a bond angle interaction
but I'm not quite sure of the structue of the file I have to provide.
I saw an old email in the list were it says that:

"What you need to give is the magnitude of the force F(r,phi)/r on one of the
outer beads, where r is the distance to the center bead. If you think about
it, the force needs to scale with this distance, as the potential U(phi) only
depends on the enclosed angle. Also, the force on the 1st and 3rd particle are
not equal in magnitude, as their distance to the center particle is different,
and therefore their torsion arms."

What is the structure of the input file? The User Guide is very clear
for the case of non-bonding and bonding potentail (since they only
depend on r), so the structure is r;F(r)/r;V(r) but for bond angle
interaction it is not clear.

Many thanks in advance.

Best,

Hender