These structures have been selected to demonstrate routine and advanced refinement techniques with programs OLEX2 and SHELXL. The Crystallographic_Problems file (98 MB) contains all data files and related materials except for Structure28 (separate 260 MB download). Some examples make use of Bruker programs CELL_NOW and TWINABS. Updated on June 25, 2024.
| wdt_ID | Chemical diagram | Files supplied | Theme |
|---|---|---|---|
| 1 |  |
Aspirin.p4p, Aspirtin.hkl | Hydrogen atom positions |
| 2 |  |
Structure1.p4p, Structure1.hkl | Connectivity |
| 3 |  |
Structure2.p4p, Structure2.hkl | Special position |
| 4 |  |
Structure3.p4p, Structure3.hkl | Proton transfer |
| 5 |  |
VitaminC.p4p, VitaminC.hkl | Hydrogen atom positions (pdf) |
| 6 |  |
Structure4.p4p, Structure4.hkl | Direct methods failure (pdf) |
| 7 |  |
Structure5.p4p, Structure5.hkl | Enantiomers and diastereomers (paper PDF) |
| 8 |  |
Structure6.p4p, Structure6.hkl | Connectivity. Correct MassSpec |
| 9 |  |
Structure7.p4p, Structure7.hkl | Structure building |
| 10 |  |
Structure8.p4p, Structure8.hkl | Positional disorder |
| 11 |  |
Structure9.p4p, Structure9.raw | Unexpected composition (very hard) |
| 12 |  |
Quartz.p4p, Quartz.raw | High symmetry structure |
| 13 |  |
Structure10.res, Structure10.hkl | Easy SPLIT procedure |
| 14 |  |
Structure11.res, Structure11.hkl | Water molecules and GROW. Easy example. |
| 15 |  |
Structure12.res, Structure12.hkl | Easy split example; Mn atom on a special position |
| 16 |  |
Structure13.p4p, Structure13.raw | Special position and disorder (pdf) |
| 17 |  |
Structure14.p4p, Structure14.hkl | Atomic identities and solvent disorder |
| 18 |  |
Structure15.res, Structure15.hkl | Br/Cl disorder |
| 19 |  |
Structure16.res, Structure16.hkl | Atom identification, SQUEEZE (pdf) |
| 20 |  |
Structure17.res, Structure17.hkl | Involved toluene disorder. SQUEEZE |
| 21 |  |
Structure18.res, Structure18.hkl | Idealized geometry. Acta C paper on the idealized geometry library. |
| 22 |  |
Structure19.res, Structure19.hkl | -CF3 disorder. George Sheldrick's paper on RIGU restraint. |
| 23 |  |
Structure20.res, Structure20.hkl | Video: how to use PART -1 and an idealized molecular geometry |
| 24 |  |
Structure21.res, Structure21.hkl | A tert-Bu disorder illustrates modes FIT and SPLIT as well as SADI/RIGU commands. A paper with the published structure is provided. |
| 25 |  |
Structure22.p4p, Structure22.raw | Challenging space group assignment |
| 26 |  |
Ferrocene.p4p, Ferrocene.hkl | Challenging space group assignment and positional disorder |
| 27 |  |
Structure23.p4p, Structure23.raw | Challenging space group assignment, unusual Z', metal identification! |
| 28 |  |
Ylid_twin.p4p, Ylid_twin.mul (twinned data) | https://uwmadison.box.com/s/k70kgr5y26ucyosgouopej5odb8san9u||Twinned data processing (needs TWINABS) |
| 29 |  |
Structure24.p4p, Structure24.mul (twinned data) | Non-merohedral twin |
| 30 |  |
Structure25.p4p, Structure25.raw | Pseudo-merohedral twin. PDF: Detailed example of a non-merohedral twin refinement. |
| 31 |  |
Structure26.hkl, Structure26.txt | Whole molecule disorder. PDF: unit cell parameter precision. |
| 32 |  |
Structure27.p4p, Structure27.hkl | Unexpected disorder that requires the knowledge of the chemical synthesis |
| 33 |  |
Structure28 zip file with frame data | Straightforward example of a non-merohedral twin |
| 34 |  |
Structure29.hkl, Structure29_unit_cell.txt | Compositional disorder in the main Ru complex, positional solvent disorder. Exploration of SQUEEZE and BYPASS(OLEX2). Statistical analysis of bond distances with ConQuest/Mercury. |
| 36 |  |
Structure30.p4p, Structure30.hkl | Compositional disorder on a special position |
| 37 |  |
Structure31.p4p, Structure31.hkl | Pseudo-merohedral twinning |
| 38 |  |
Structure32.cif | Unexpected composition |
| Files supplied | Theme |
Twinned datasets are available for selfstudy: twin1 (organic compound), twin2 (organometallic compound).