Tuesday, August 31, 2010

Spiral codes in "An atlas of fullerenes"

I finally got my own copy of Fowler and Manolopoulos's "An Atlas of Fullerenes" from the MIT coop at Kendall square last weekend. In the appendix of this book, there is a complete list of spiral codes for fullerenes with less or equal than 100 carbon atoms. So one can simply follow the spiral code to create the physical model of corresponding fullerene. More importantly, if we followed the simple weaving rule, no other information except the spiral code is required to make the correct physical model!

I made the only isomer of C72 and C74, which satisfies the IPR (isolated-pentagon rule) requirement, based on the spiral codes listed in the appendix immediately when I was back to Taiwan yesterday. Just as expected, the bead model of C72 has D6d symmetry, and the bead model of C74 has D3h symmetry as shown in the book.

Spiral codes:
C72: 1 7 9 11 13 18 22 24 27 34 36 38

C74: 1 7 9 11 14 23 26 28 30 32 35 38

Saturday, August 14, 2010

A few pictures from my workshop at ICCE

I gave a three-hour workshop, "Chemistry, Geometry and Art", at the 21st International Conference on Chemical Education at the Taipei International Convention Center. I made a 30-min introduction to the background information (slides) first, and then let all participants to work on two projects: C20 and C6o.
People seem to have fun in this workshop.

Beaded Car Seat

I took a taxi to the Taipei International Convention Center for my workshop for the ICCE, I found this beaded seat cover in the back seat of the taxi. It is made by the standard right-angle weave with bean-shaped beads.

Beads for the workshop

I bought 15 packages of 10mm beads (about 10,000 beads) for the workshop of ICCE. Qian-Rui Huang and I have also made many bead models of C60 (more than 20 in total). In addition, I have also made some beaded C70s and C80s. Most of them have been given away to the participants of this conference as souvenirs.

Effect of nonhexagon on the graphene surface

I made a few bead models of [n]-circulene (n=5,6,7,8) to illustrate the influence of nonhexagon on the local Gaussian curvature at nonhexagons.
One can easily see that [6]-circulene (coronene) is planar. But [5]-circulene (corannulene) has positive Gaussian curvature (bowl-shape), and [7]- or [8]-circulene have negative Gaussian curvatures (saddle-shape).

I made these models for the workshop for the 21st International Conference on Chemical Education (ICCE) yesterday after. However, I don't have chance to use them.