June 12

The third Mathematical Crystallography minisymposium was entitled Structure-Building Principles. Unfortunately, I forgot to recharge my camera battery, so I didn’t take pictures. Fortunately, Massimo Nespolo did.

Jean-Guillaume Eon talked about Imprimitivity in Non-Crystallographic Nets. The automorphism group of a periodic net graph might not be crystallographic, and if it is not, we call the net non-crystallographic. Some descriptive machinery is introduced, and using such machinery, one can dissect non-crystallographic nets via their (labeled) quotient graphs.

Henrik van Lengerich talked about Self Assembly and the Structure of Matter. An objective structure can be constructed by applying a finite subgroup of O(3) to an object, and obtain a structure consisting of copies of that object. Experiments show that some structures are unlikely to assemble properly because during assembly, they get trapped in an incomplete metastable state. Thus successful freely assembled structures require design, and Langevin dynamics are presented as a candidate design regime.

Mike Zaworotko talked about Why Topology Matters to Crystal Engineers. Crystal engineering is aimed at applications like gas storage and capture, and in these applications, “the material is the application.” Metal-organic materials are designed at the molecular or atomic level using as building blocks highly symmetric polygonal or polyhedral molecular building blocks.

It was the last day of the conference, an appropriate day for slumming, so we went to a local Olive Garden.