1. What are the problems of (science) education in science in US? (E. O. Wilson) It's the culture (ASU Chem: 1/3 foreign-born, mostly recent hires) The culture can be changed. Cf. Ireland

2. What should we do? Convince David Nelson to convince NSF to work on changing the national culture.

3. Alright, what about Solid State Chemistry? First, change the name. Materials Chemistry? It's no accident we are part of DMR. Educate our colleagues. "Everyone" knows biological chemistry is a big growth area materials chemistry is the other. make peace with engineers

4. Why interest in nets? The Cambridge Crystal Structure database is growing exponentially (t 2 = doubling time): all structures t 2 = 9.3 yr extended structures based on periodic nets t 2 = 5.7 yr metal-organic frameworks (MOFs) t 2 = 3.9 yr Thanks to Nate Ockwig

5. What are the topics needed but missing in Chemistry curriculum? Mathematics of periodic structures Fourier transforms Space groups Periodic nets and surfaces (e.g. gyroid) Crystallography Diffraction methods Diffraction by point scatterers Direct methods The facts! Crystal structures: MgCu 2 as well as NaCl Materials: zeolites, magnetic materials, cement, minerals

6. What do we know about electron density in crystals? 1.It is always positive 2.It is close to zero “almost” everywhere this is very non-random basis of "direct methods"

7. The charge-flipping algorithm (Osl á nyi & S ü to, 2004) F(g) + random phases (r)(r) FT flip '(r)'(r) FT -1 new phases = F ' (g)/| F ' (g)| original F(g) + new phases FT flip the sign of the electron density of the lowest fraction of all pixels. Fraction may be as much as 80% notice that all we are doing is finding new phases

8. How do we know what’s happening? R =  ||F ' (h)|-|F(h)|/  |F(h) Note that R does not measure agreement with “model” (if no pixels flipped R = 0)

9. Variation of R with iteration number for C 6 Br 6

10. First application to a real crystal C 6 Br 6 Z C = 6, Z Br = 35 projected density after one run mean of six note that the molecules are slightly inclined (20°) to the plane of projection J. S. Wu, J. C. H. Spence, M. O'Keeffe, T. L. Groy. Acta Crystallogr. (2004), A60, 328-330.

11. The srs net is chiral (symmetry I4 1 32). The dual is the enantiomorph. Here two srs nets of opposite hand are intergrown to form a centrosymmetric structure (srs-c) (symmetry Ia-3d). The surface separating the two nets is the G minimal surface (gyroid)

12. Alan Schoen's gyroid – periodic minimal surface G Fragments of two srs nets The same – "blown up" A "tile" of the G surface

13. The 5-coordinated net fcz As a 3 2.4.3.6 tiling of the G surfaceAs a 2[6 2.10 3 ] + 3[3 8.4 2 10 2 ] tiling of space (the set of all tiles fill space completely)

14. SU-M (ASU-17) a germanate with cubic cell 51.3 Å X. Zou, T. Conradsson, M. Klinstedt, M. S. Dadachov & M. O'Keeffe, Nature (2005)

15. The structure is based on the fcz tiling of G!

16. The hierarchical nature of the SU-M structure

17. SU-MB symmetry I4 1 32. Chiral! one set of pores of SU-M blocked by six 7 Ge clusters. These are the clusters from ASU-16 etc. one cage in SU-MB clusters in SU-MB cage faujasite "supercage"