Practical hints and tips for solution of pseudo-merohedric twins: three case studies.
1Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA.
Summary
Structure solution for twinned small molecules is challenging when components are similar. This study offers practical tips and worked examples for solving these complex crystallographic structures.
Area of Science:
- Crystallography
- Materials Science
Background:
- Pseudo-merohedral twinning is common in small-molecule crystallography.
- Structure solution is difficult when twin-component volume fractions are similar.
Purpose of the Study:
- To provide practical hints and tips for solving complex twinned crystal structures.
- To illustrate structure solution strategies using three worked examples.
Main Methods:
- Analysis of three case studies involving pseudo-merohedral twinning.
- Application of crystallographic structure solution techniques.
- Utilizing unconventional space-group settings where beneficial.
Main Results:
- Demonstrated structure solution for a two-component pseudo-orthorhombic twin.
- Successfully solved a threefold pseudo-hexagonal twin using an unconventional setting.
- Determined the structure of a fourfold pseudo-tetragonal twin.
Conclusions:
- All three solved structures were monoclinic crystals exhibiting twinning due to unit-cell metrics mimicking higher symmetry systems.
- The presented methods offer valuable guidance for crystallographers facing similar twinning challenges.
Keywords:
HKLF 5 formatpseudo-hexagonalpseudo-merohedrypseudo-orthorhombicpseudo-tetragonalreticulartwinningMore Related Videos
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