Hi Espresso-verse,
I know there are a few threads of this nature already in the archives,
but I have a clarifying question about the tabulated angle potential.
I am building a coarse grained polymer from tabulated potentials
calculated by probability densities. The backbone is composed of beads
of type B and each B bead has one pendant group of type A. Therefore,
I have nonbonded potentials, AB and BB bonded potentials, and BBB and
ABB angular bond potentials.
The UG states that the force must be scaled with the inverse length of
the connecting vectors. For the angular bond potentials, do I need a 3
dimensional map of V(r,phi) in order to calculate this? Right now I
only have V(r) and V(phi)
The part that confuses me is that if one builds the tabulated file
like this
#N_points 0 3.14159
phi (-dV/dphi)/r V(phi)
....
....
Then the r to use is not obvious to me.