Dept of Energy CSGF magazine 2007-8 -- DOE Lab Research

Oak Ridge National Laboratory

It’s MADNESS

“Software gets slower faster than hardware gets faster.”
— Nicklaus Wirth, 1995

Robert Harrison has a beef with Wirth’s Law. He’s not saying software evolution hasn’t kept up with the hardware in some cases, just that it doesn’t have to be a self-fulfilling prophecy. Harrison, group leader of the Computational Chemical Sciences Group at ORNL, is working ahead of the game. He is part of a team developing MADNESS (Multi-resolution ADaptive Numerical Evaluation for Scientific Simulation), a next-generation software code intended from the outset to run on petascale computers still under construction.

The idea behind MADNESS is to harness the full capacity of petascale machines to solve problems that require complex quantum mechanical calculations. It is designed to be particularly useful for solving multi-scale problems in not just two or three dimensions, but up to 9 dimensions — calculations that would be unthinkable without massively parallel systems and a new application of quantum wave methodology.

“Our goal at the outset was to be very open-ended,” he says. Therefore, MADNESS can run on existing systems, but should not be limited by ever-expanding hardware capacity.

One of the first applications to use MADNESS will be a simulation of the chemistry of heavy elements. The goal, explains Harrison, is to understand how to separate and reprocess spent nuclear fuel, thereby reducing waste and increasing its useful life. Exploring new fuel separations plants is a strategic goal at DOE, but doing the thousands of required experiments on spent fuel would be a practical impossibility. Realistic simulations of the behavior of uranium, cesium and other radioactive isotopes in a separation scenario could reduce experimental work and increase understanding of the fundamental behavior of this class of elements, says Harrison.

“People say nanoscale is different,” says Harrison. “Well, petascale is different. It allows you to harness the power of complexity. We are just at the beginning to learning what it can do.”