branched polymer dihedrals

[skfegan]

The dihedral angles are used to calculate the conformational entropy.

At the residue level, we need to define the dihedrals. The current code works for linear polymers where the residues are bonded together in the order listed in the molecule topology. To work for branched polymers, the search for the 4 points defining a dihedral angle between bonded residues would have to be more nuanced.