Properties describing the pucker mode:
| C1'_endo | O4'_exo | C2'_endo |
| C1'_exo | C2'_exo | C3'_exo |
| C3'_endo | C4'_exo | C4'_endo |
| O4'_endo |
Properties describing the glycosyl bond: anti, syn
Others conformation properties:
| type_A | $$ | C3'_endo and anti |
| type_B | $$ | C2'_endo and anti |
| helix | $$ | Conformation used to build standard A-form helix. |
For the residues, using an empty properties list ( { } ) means that any type of conformation will be tested.