| Allowed Value | Details |
|---|---|
| T | special-position constraints on atomic displacement parameters |
| TU | both constraints applied |
| U | Uiso or Uij restraint (rigid bond) |
| Allowed Value | Details |
|---|---|
| T | special-position constraints on atomic displacement parameters |
| TU | both constraints applied |
| U | Uiso or Uij restraint (rigid bond) |