CBEN supercomputer helps decipher phenomena of nanotubes

CBEN supercomputer helps decipher phenomena of nanotubes
…………………………………………………………………

BY JADE BOYD
Rice News Staff

Rice University
and IBM today announced a research relationship that will
provide nanotechnology researchers at Rice’s Center
for Biological and Environmental Nanotechnology (CBEN) with
a supercomputer powerful enough to decipher the quantum
phenomena of carbon nanotubes and other nanomaterials.

CBEN researchers
plan to use the supercomputer to find new ways to use nanomaterials
to treat and diagnose disease and to clean pollutants from
the environment.

Through a Shared
University Research award from IBM, CBEN has received a
high-performance computing system, the 16-processor eServer
p690, also known as Regatta. The new supercomputer has doubled
CBEN’s existing computing capacity, providing CBEN
researchers with the intense computing power needed to solve
incredibly complex mathematical questions relating to molecular
structure.

“The unique
properties of carbon nanotubes will make them useful in
more ways than anyone can imagine, but many applications
require a detailed understanding of the mechanical, structural
and electronic properties of nanotubes,” said Richard
Smalley, University Professor and founding director of CBEN.
“Through its generosity, IBM is supplying CBEN researchers
with the powerful computers needed to tackle these complex
quantum mysteries.”

The IBM eServer
p690 is based on IBM’s next-generation POWER4 microprocessor,
a system on a chip containing two one-gigahertz-plus processors.
The p690 system also features self-healing technologies
that can help provide uninterrupted operation, even through
major power outages and system failures.

Funded by the
National Science Foundation, CBEN is the only academic research
center in the world that is dedicated to studying the interaction
of nanomaterials and living organisms and ecosystems.

Carbon nanotubes
are single molecules of carbon that can contain millions
of atoms arranged in hollow cylinders. These tubes are just
one-billionth of a meter in diameter but can stretch a millimeter
or more in length. That’s analogous to a 15-mile-long
garden hose.

Calculations
on the IBM eServer p690 are showing that even small imperfections
in the tubes can drastically affect their mechanical and
electrical properties.

“What happens
when you remove a couple of atoms out of every thousand?”
Gustavo Scuseria, the Welch Professor of Chemistry, asked.
“What we’re finding is that there are dramatic
differences — greater than anything we had expected.”

Part of the reason
that nanotubes behave so differently than theorists have
envisioned is they are so small. At the nanometer scale,
the strange and counterintuitive forces of quantum mechanics
play a critical part in determining electric conductance
properties. With larger wires and circuits — even the
transistors on today’s smallest microchips — quantum
effects play a negligible role, meaning engineers can ignore
them altogether.

To find out exactly
how the nanotubes will behave, Scuseria’s research
team uses the supercomputers to calculate precisely what
happens as individual electrons and photons interact with
carbon atoms in a nanotube.

Even the eServer
p690, which can perform hundreds of millions of calculations
per second, takes up to a week to solve the equations describing
a section of nanotube containing a few thousand atoms.

When complete,
IBM expects this research will result in the development
of linear scaling theories and algorithms that will represent
a major step forward in theoretical molecular and biomolecular
science. Subsequently, chemical scientific software applications
will be modified to incorporate these new algorithms, and
IBM plans to take the lead in incorporating this knowledge
into its technology and products.