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INTRODUCTION
The results from a third structure determination by powder diffractometry (SDPD) round-robin are summarized. From the 175 potential participants
having downloaded the powder data, 9 have sent a total of 12 solutions (8 and 4 respectively
for samples 1 and 2, a calcium tartrate tetrahydrated and a lanthanum tungstate). They used 7 different
computer programs for structure solution (ESPOIR, EXPO, FOX, PSSP, SHELXS, SUPERFLIP, TOPAS),applying either the Patterson or direct methods,
direct space methods, or the charge flipping approach.
INTRODUCTION
The results from a third structure determination by powder diffractometry (SDPD) round-robin are summarized. From the 175 potential participants
having downloaded the powder data, 9 have sent a total of 12 solutions (8 and 4 respectively
for samples 1 and 2, a calcium tartrate tetrahydrated and a lanthanum tungstate). They used 7 different
computer programs for structure solution (ESPOIR, EXPO, FOX, PSSP, SHELXS, SUPERFLIP, TOPAS),applying either the Patterson or direct methods,
direct space methods, or the charge flipping approach.
CONCLUSION
Solving a structure from powder data remains a hard job, an order of magnitude harder than solving a problem with similar complexity from single crystal data. Nevertheless, a few more steps in the direction of routine were accomplished since the two previous round-robins : that time, not only the computer
program developers were successful, but also some more standard users. No result was obtained from crystal structure
prediction experts.
CONCLUSION
Solving a structure from powder data remains a hard job, an order of magnitude harder than solving a problem with similar complexity from single crystal data. Nevertheless, a few more steps in the direction of routine were accomplished since the two previous round-robins : that time, not only the computer
program developers were successful, but also some more standard users. No result was obtained from crystal structure
prediction experts.
REFERENCES
• Adil, K., Le Bail, A., Dujardin, G. & Maisonneuve V. (2007). Polyhedron 26, 2493- 2497. • Chambrier M.H., Le Bail A. & Goutenoire F. (2008). http://www.crystallography.net/• Clegg, W. & Teat, S.J. (2000). Acta Cryst. C56, 1343-1345.• Le Bail A. (2003). COD1000005 - http://www.crystallography.net/ • Le Bail, A. & Cranswick, L.M.D. (2001). Commission on Powder Diffraction IUCr Newsletter 25, 7-9.• Le Bail, A. & Cranswick, L.M.D. (2003). Commission on Powder Diffraction IUCr Newsletter 29, 31-34.• Le Bail, A., Bazin, D., Daudon, M. & Maisonneuve, V. (2008). http://www.crystallography.net/• Zhu, J.H., Wu, H.X. & Le Bail, A. (1999). Solid State Science, 1, 55-62.
REFERENCES
• Adil, K., Le Bail, A., Dujardin, G. & Maisonneuve V. (2007). Polyhedron 26, 2493- 2497. • Chambrier M.H., Le Bail A. & Goutenoire F. (2008). http://www.crystallography.net/• Clegg, W. & Teat, S.J. (2000). Acta Cryst. C56, 1343-1345.• Le Bail A. (2003). COD1000005 - http://www.crystallography.net/ • Le Bail, A. & Cranswick, L.M.D. (2001). Commission on Powder Diffraction IUCr Newsletter 25, 7-9.• Le Bail, A. & Cranswick, L.M.D. (2003). Commission on Powder Diffraction IUCr Newsletter 29, 31-34.• Le Bail, A., Bazin, D., Daudon, M. & Maisonneuve, V. (2008). http://www.crystallography.net/• Zhu, J.H., Wu, H.X. & Le Bail, A. (1999). Solid State Science, 1, 55-62.
The third Structure Determination by Powder Diffractometry Round Robin (SDPDRR-3)L.M.D. Cranswick and A. Le Bail
Canadian Neutron Beam Centre, National Research Council Canada, Building 459, Chalk River Laboratories, Chalk River ON, Canada, K0J 1J0. Email : [email protected]é du Maine, Laboratoire des Oxydes et Fluorures, CNRS UMR 6010, Av. O. Messiaen, 72085 Le Mans, France. Email : [email protected]
The third Structure Determination by Powder Diffractometry Round Robin (SDPDRR-3)L.M.D. Cranswick and A. Le Bail
Canadian Neutron Beam Centre, National Research Council Canada, Building 459, Chalk River Laboratories, Chalk River ON, Canada, K0J 1J0. Email : [email protected]é du Maine, Laboratoire des Oxydes et Fluorures, CNRS UMR 6010, Av. O. Messiaen, 72085 Le Mans, France. Email : [email protected]
Sample 1 : CaC4H4O6.4H2O
Sample 2 : La18W10O57
Conventional X-rays
Synchrotron Neutron
