There are two main conformations corresponding to the symmetry operation connecting two adjacent monomers: 'a' for reflection and 'b' for rotation.

Conformer polym-b_CAM-B3LYPp2p is 0.7 meV/monomer higher in energy than 'a'.
Conformer molec-b_CAM-B3LYPp2p is 0.4 meV higher in energy than 'a'.