An experiment in crystal structure prediction by popular vote

Crystal Growth and Design

Volumn 6, Issue 9, 2006, Pages 1985-1990

  Day, Graeme M ^a   Motherwell, W D Sam ^b  

^a UNIVERSITY OF CAMBRIDGE   (United Kingdom)

^b CAMBRIDGE CRYSTALLOGRAPHIC DATA CENTRE   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 33749004817     PISSN: 15287483     EISSN: None     Source Type: Journal    
DOI: 10.1021/cg060313r     Document Type: Review

References (13)

1. Day, G. M.; Shan, N.; Motherwell, W. D. S.; Jones, W. Cryst. Growth Des. 2004, 4, 1327-1340.
2. Price, S. L. CrystEngComm 2004, 6, 344-353.
3. Gavezzotti, A. CrystEngComm 2003, 5, 429-438.
4. Day, G. M.; Price, S. L.; Leslie, M. J. Phys. Chem. B 2003, 107, 10919-10933.
5. Hamad, S.; Moon, C.; Catlow, C. R. A.; Hulme, A. T.; Price, S. L. J. Phys. Chem. B 2006, 110, 3323-3329.
6. Galton, F. Nature 1907, 75, 450-451.
7. Both molecules were subjected to a small manual screen of crystallization conditions, more details of which are provided as Supporting Information. The crystal structure of molecule I was solved from a crystal grown by slow evaporation from a 1:1 acetone/water solution. The crystal structure of molecule II was originally solved from a crystal grown from a toluene solution at high supersaturation. After the test, a higher-quality crystal structure of molecule II was determined from a crystal grown from acetonitrile.
8. Day, G. M.; Motherwell, W. D. S.; Jones, W. Cryst. Growth Des. 2005, 5, 1023-1033.
9. The energy minimized version of the experimentally observed crystal structures were used in the test instead of the X-ray determined structures because this is the situation in true crystal structure prediction studies, where predictions are made based on the calculated structures before a structure is determined by experimental methods.
10. The prize was generously donated by the Cambridge Crystallographic Data Centre, and any participants correctly guessing a crystal structure were entered in a draw.
11. Macrae, C. F.; Edgington, P. R.; McCabe, P.; Pidcock, E.; Shields, G. P.; Taylor, R.; Towler, M.; van de Streek, J. J. Appl. Crystallogr. 2006, 39, 453-457.
12. Most participants (37 of 50 for molecule I and 27 of 38 for molecule II) indicated that they analyzed the structures in Mercury, so they could measure the geometries of intermolecular contacts, such as hydrogen bonds. The sample size of people who only used the printed packing diagrams, which had no intermolecular distances shown, are too small to assess whether the lack of such information significantly affected the choice of structures.
13. In the case of 5-fluoro-2-oxindole, an analysis of the Cambridge Structural Database (CSD) of all published molecular crystal structures might have been misleading. The non-fluorinated 2-oxindole has one reported crystal structure (CSD refcode ZOYLII), with hydrogen-bond dimers instead of the chains seen in 3-fluoro-2-oxindole. A wider search of the CSD shows a nearly equal distribution of dimers and chains in molecules containing the same NH-C=O fragment in a planar five-membered ring.