1. Lachlan M. D. Cranswick (l.m.d.cranswick@dl.ac.uk) http://www.ccp14.ac.uk Slide 1 SDPDRR-II (Structure Determination by Powder Diffractometry Round Robin - 2 )  WWW: http://www.cristal.org/sdpdrr2/  Started: Monday 9th September  Part 1 (powder indexing):  Start: Monday 9th September  Finish: Sunday 13th October  8 samples  1 - 3 : Powder indexing and structure solution  4 - 8 : Powder Indexing only  > 100 downloads of the data (samples 1 to 3)

2. Lachlan M. D. Cranswick (l.m.d.cranswick@dl.ac.uk) http://www.ccp14.ac.uk Slide 2 SDPDRR-II - Indexing Results  WWW: http://sdpd.univ-lemans.fr/sdpdrr2/results/  6 returns/100 downloads = 6% return rate

3. Lachlan M. D. Cranswick (l.m.d.cranswick@dl.ac.uk) http://www.ccp14.ac.uk Slide 3 SDPDRR-II - Sample 1  WWW: http://sdpd.univ-lemans.fr/sdpdrr2/results/  Organisers:10.323 7.395 8.535 90 91.29 90  Reduced cell: 7.395 8.535 10.323 91.29 90.00 90.00  P1:10.318 7.393 8.527 90 91.3 90  P2:10.321 7.392 13.236 90 139.90 90  P3:10.322 14.787 8.529 90 91.35 90  Reduced cell: 8.529 10.322 14.787 90.00 90.00 91.30  P4:No solution  P5:8.523 10.327 7.397 90 90 91.34  P6:8.525 7.394 13.230 90 128.748 90

4. Lachlan M. D. Cranswick (l.m.d.cranswick@dl.ac.uk) http://www.ccp14.ac.uk Slide 4 SDPDRR-II - Sample 2  WWW: http://sdpd.univ-lemans.fr/sdpdrr2/results/  Organisers:11.239 8.194 19.943 90 106.727 90  Reduced cell: 8.194 11.239 19.875 106.06 90.00 90.00  P1:19.880 8.195 11.242 90 106.06 90  P2:11.242 8.195 19.948 90 106.72 90  P3:19.878 8.193 11.240 90 106.06 90  P4:19.880 8.194 11.243 90 106.06 90  P5:11.244 19.882 8.196 90 90 106.06  P6:11.243 8.195 19.949 90 106.72 90

5. Lachlan M. D. Cranswick (l.m.d.cranswick@dl.ac.uk) http://www.ccp14.ac.uk Slide 5 SDPDRR-II - Sample 3  WWW: http://sdpd.univ-lemans.fr/sdpdrr2/results/  Organisers:18.881 18.881 18.881 90 90 90 (vol 6734Å 3 )  P1:13.349 13.349 9.439 90 90 90 (Tet - 1638Å 3 )  P2:18.878 18.878 18.878 90 90 90  P3:13.354 13.354 9.442 90 90 90 (Tet - 1638Å 3 )  P4:No Solution  P5:18.878 18.878 18.878 90 90 90  P6:18.88 18.88 18.88 90 90 90

6. Lachlan M. D. Cranswick (l.m.d.cranswick@dl.ac.uk) http://www.ccp14.ac.uk Slide 6 SDPDRR-II - Sample 3 Tetragonal or Cubic?  2 participants (1 and 3) obtained the same tetragonal cell instead of the correct cubic.  Possibly due to default volume restrictions in the programs used(?)  What happens if you run LePage (via Chekcell) followed by a “parsimony of extra reflections” check on the tetragonal solution

7. Lachlan M. D. Cranswick (l.m.d.cranswick@dl.ac.uk) http://www.ccp14.ac.uk Slide 7 SDPDRR-II - Sample 3: Tetragonal: 1 peak unmatched - 46 hkl’s (P42MC et al) to match 25 reflections

8. Lachlan M. D. Cranswick (l.m.d.cranswick@dl.ac.uk) http://www.ccp14.ac.uk Slide 8 SDPDRR-II - Sample 3: Tetragonal: Running LePage shows a cubic cell (18.885Å)

9. Lachlan M. D. Cranswick (l.m.d.cranswick@dl.ac.uk) http://www.ccp14.ac.uk Slide 9 SDPDRR-II - Sample 3: Visual inspection of cubic cell implies “bad”peak could still be an impurity

10. Lachlan M. D. Cranswick (l.m.d.cranswick@dl.ac.uk) http://www.ccp14.ac.uk Slide 10 SDPDRR-II - Sample 3: Cubic: 37 hkl’s to match 25 reflections (I23 et al) (vs 46 hkl’s in tetragonal)

11. Lachlan M. D. Cranswick (l.m.d.cranswick@dl.ac.uk) http://www.ccp14.ac.uk Slide 11 SDPDRR-II - Samples 4 to 8  WWW: http://sdpd.univ-lemans.fr/sdpdrr2/results/  Only one response - using the EFLECH/Index software of Joerg Bergmann ( http://www.bgmn.de/related.html )  S4:none suggested  S5:6.011 16.937 18.229 90 90 92.19  S6:none suggested  S7:4.417 11.479 17.126 77.87 85.09 82.67  S8:3.796 9.368 28.915 90 90 90  Summary: Powder indexing is not easy and not routine!