Topological Crystallography Commemorating the fourth centennial anniversary of the publication of Kepler‘s pamphlet (1611) New-Year's gift concerning six- cornered snow Toshikazu Sunada Meiji University August 26, 2011 at Sendai
The purpose of this talk
Legacy of Ancient Greece in crystallography
Regular convex polyhedra
Archimedean Solids
Johaness Kepler ( )
“New Year’s gift concerning six-cornered snow” (1611)
Face-centered cubic lattice (fcc)
Discovery of crystal structures
Diamond and Lonsdaleite
Graphs associated with chemical compounds
Graphs
Fundamental finite graphs and building blocks
How to get the fundamental finite graphs
Canonical map
How to get the crystal from a building block
Examples of fundamental finite graphs Diamond and Lonsdaleite 3D Kagome lattice (comprised by corner-sharing tetrahedra)
Example
Diamond and Honeycomb
Enumeration of vanishing subgroups
Kronecker’s dream in crystallography
Canonical placement
Canonical placement is most symmetric
Algorithm
Examples (Classical lattices)
A hypothetical crystal (1)
A hypothetical crystal (2) (3D Kagome lattice)
A hypothetical crystal (3)
A hypothetical crystal (4)
Open problems
Final Remarks
Graph-theoretic Abel-Jacobi maps
N.I.Lobachevskii