| Ligand | AA | Ligand | δ (Å) | θ (˚) |
| 3S | Arg 63 NH | N | 2.08 | 166 |
| Arg 63 O | HN | 2.10 | 161 | |
| 3Se | Arg 63 NH | N | 2.52 | 150 |
| Arg 63 O | HN | 2.15 | 158 |