Monday, October 26, 2009

New P-Type surface

I created a new P-surface with eight unit cells (2x2x2) using white and red beads last weekend. In total, 2880 beads are used. (Note that 90 beads are needed to create a C60.) Unlike previous two P-surfaces, I use red beads for octagons this time. The weaving process for creating a large beaded structure usually takes a long time and is prone to error.

Since the whole weaving process is essentially serial, the beads have to be added one by one along a single string of thread. So, once an error was made in the past, it is difficult to correct it without untieing all the beads up to that point the error was made.

The errors I made are usually something like using 9 beads to create an octagons (3 or 4 times out 128 octagons in the structure) and using 7 beads for hexagon (only 1 times). It is easy to understand why these errors occur more frequently for octagons, since it is more difficult to distinguish octagon and nonagon.

The first P-type structure Chuang and I made together has been given away to Bob Silbey as a gift in the summer of 2008. I made the remaining two P-surfaces by myself.




Silbey's 65 Birthday Symposium. I was in the second row far left.

(photo taken from http://web.mit.edu/newsoffice/2005/silbey.html)