The Department of Energy's Office of Science and the National Nuclear Security Administration (NNSA) have issued a joint Request for Proposals for advanced scientific computing research. DOE expects to fund $67 million annually for three years to five years under its Scientific Discovery through Advanced Computing (SciDAC) research program. Scientific computing, including modeling and simulation, has become crucial for research problems that are insoluble by traditional theoretical and experimental approaches, hazardous to study in the laboratory, or time-consuming or expensive to solve by traditional means. Research proposals funded under the SciDAC program will help create a comprehensive, scientific computing software infrastructure that integrates applied mathematics, computer science and computational science in the physical, biological and environmental sciences for scientific discovery on petascale computers. Petascale computers will be capable of doing thousands of trillions of calculations per second. A simulation that would take 19 years to run on today's teraflop (1 trillion calculations/second) computers will only require a single week on a petascale computer. "As high end computation continues to develop and displays its scientific predictive power, more and more scientists are seeing computational simulation as a powerful means for scientific discovery," Dr. Raymond L. Orbach, Director of DOE's Office of Science said. "This call for proposals is evidence of the commitment of the Office of Science to provide this opportunity. SciDAC brings together scientists with their counterparts in applied mathematics and computer science, together with major computational facilities, to solve basic and applied science problems of major magnitude and significance." Proposals are specifically requested with applications in a number of areas of science related to the department's missions: accelerator science, astrophysics, climate modeling, computational biology, fusion science, groundwater modeling, high energy physics, nuclear physics, quantum chromodynamics, materials sciences, radiation transport and turbulence. Research under the program may also help develop applications and a new generation of data management and tools for the large data sets obtained from large experimental facilities and from high end simulations. In March 2000, DOE's Office of Science proposed SciDAC, an ambitious program to build the scientific computing software and hardware infrastructure needed to realize the full potential of terascale computers for advancing scientific discovery and the state of the art in engineering. In the five years of its existence, the program has demonstrated the benefits of teaming computational scientists, computer scientists and applied mathematicians in tackling scientific problems. Through the SciDAC program, research teams have leveraged their expertise to more accurately model complex scientific and engineering phenomena. For example, SciDAC researchers studied detailed simulations of large systems that were previously inaccessible such as heat diffusion in fusion reactors. These results were incorporated into the design of ITER, the planned international fusion energy experiment. In another SciDAC effort, the sophistication of climate research modeling was developed to such a level that reliable comparisons with experimental data can now be made. In yet another area of science, new quantum simulations enabled by SciDAC have suggested the existence of a new state for hydrogen at low temperatures that may undergo a phase transition from superconducting to superfluid. The SciDAC program is structured to be interdisciplinary and multi-institutional. University researchers' collaborations with researchers in federal laboratories, including DOE national laboratories, are encouraged. Letters of intent are due by January 23, 2006, and formal applications are due by March 6, 2006. Details about the Request for Proposals are available at: its Web site. Additional information about SciDAC is available at: www.scidac.org.