A computer code written recently to simulate how materials behave on the microscale has had a macroscale impact on scientific computing. Researchers from Oak Ridge National Laboratory, the National Energy Research Supercomputing Center, and colleagues wrote the code in 1998 to simulate the behavior of iron atoms and thereby provide a better microscopic understanding of metallic magnetism. Using a new "spin dynamics" technique developed at Ames Laboratory, the team wrote a computer program that executed the equations of motion for as many as 1,024 atoms. When this work was performed using special supercomputers, the running code was able to sustain a record-setting speed that surpassed one thousand billion operations per second (or 1 teraflop). This work won the 1998 Gordon Bell Award for the best performance of a real application code, and was the 2000 Computerworld Smithsonian Laureate for the first teraflop-scale application code. This remains the fastest sustained real application ever run on supercomputers.

Scientific Impact: This calculation demonstrated that terascale computing could lead to new science and provided new insight into the behavior of magnetic materials. High-performance computing has become a crucial tool for scientific discovery in many fields, including materials research, climate prediction, and bioinformatics.

Social Impact: Understanding of metallic magnetism is key to many technologies, including magnetic data storage devices and motors. This work has important implications for future research in high-performance computer disk drives and magnetic recording media, as well as power generation and use.

Reference: Balazs Ujfalussy, Xindong Wang, Xiaoguang Zhang, D. M. C. Nicholson, W. A. Shelton and G. M. Stocks, Oak Ridge National Laboratory; A. Canning, NERSC, Lawrence Berkeley National Laboratory; Yang Wang, Pittsburgh Supercomputing Center; B. L. Gyorffy, H. H. Wills Physics Laboratory, UK. "High Performance First Principles Method for Non-Equilibrium States in Magnets," in Proceedings of SC98 Conference, November 7-13, 1998, Orlando, Florida, sponsored by IEEE Computer Society and ACM SIGARCH.

URL: http://theory.ms.ornl.gov/~gms/G_Bell/decades.htm

Technical Contact: Daniel A Hitchcock, Mathematical, Information, & Computational Sciences Division, Office of Advanced Scientific Computing Research, 301-903-6767

Dale Koelling, Condensed Matter Physics & Materials Chemistry Team, Office of Basic Energy Science, 301-903-2187

Press Contact: Jeff Sherwood, DOE Office of Public Affairs, 202-586-5806

SC-Funding Office: Office of Advanced Scientific Computing Research and Office of Basic Energy Science