Crystallographic problems

These structures have been selected to demonstrate routine and advanced refinement techniques with programs OLEX2 and SHELXL. The Crystallographic_Problems file (90 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.

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)||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
Compositional disorder on a special position
Files supplied Theme