Scientific Frontline® On-Site Search Engine by Google Co-op

Current UTC Time
 
News Home, where you will find the "Current Top Stories"The Communication Center contains current news briefs from major Universities, NASA, ESA, and the top three Aviation Mfg.Science section contains all the latest knowledge in Medical Research, Archeology, Biology, and other General Science NewsCurrent Earth Science and Environmental discoveries.The E.A.R., Environmental Awareness Report. E.A.R. will keep you advised of Environmental Alerts, Government, University, and public projects. All the current space discoveries from Hubble, Spitzer, Chandra X-Ray, ESO, Gemini, Subaru, ESA, NASA, and many more. The latest in space theories from leading astronomers and scientist from around the world.The Space Weather Forecast Center by Scientific Frontline, Current up-to-date space weather, forecasts, alerts and warnings. Images from SOHO, GOES, and STEREO. Plus solar observations from Erika RixCurrent space missions newsThe Cassini Main Page. Containing all the latest news from the Cassini Spacecraft around Saturn. Leading into Cassini status reports, The Cassini Gallery of all the latest images from Cassini. Seeing Saturn and all her moons like never before.Daily Sky maps, Celestial Events Calendar.Observatories Gallery, images from The Great Observatories and other leaders in astronomy.The Stellar Nights  Gallery, An amateur astronomical collection from John Crilly, Richard Handy, Erika Rix, and Paul RixCloudy Nights Telescope Reviews / An Atronomical Community.The latest in Computer, Nanotechnology, and General Technological advancements.The latest in Aviation achievements in civil, military, and space aviationThe World News Report,  news from the Voxant Viral Syndication, known as the Newsroom. Contains the latest videos from major news sources.The news archive from Scientific Frontline's past articles. A world of knowledge at your fingertips.Abstracts, Journals, and Technical papers maintained by Scientific Frontline. The Gateway to all the galleries in the Scientific Frontline collectionThe Scientific Frontline Discussion Rooms. Open to the public.upcoming events, seminars, and lectures from major universities, government, and privately sponsored programsSite Related links from major universities, government and private research labs.Assorted Downloads related to space, science, aviation, including screensavers and ASTROMONY SOFTWARE, and other endorsed programs.Words from Heidi-Ann Kennedy, Director Scientific FrontlineThe foundation of an online publication by SFL ORG. News Network called Scientific FrontlineContact page to Scientific Frontline / SFL ORG. News NetworkDisclaimer / Legal Notice for use of the SFL ORG. News Network's publication Scientific Frontline
an online publication of the SFL ORG. Educational News Network

Computer Method May Help Humans Achieve Energy Independence From Fossil Fuels

Friday, November 7, 2008

A test run of LS3DF, which took one hour on 17,000 processors of Franklin, performed electronic structure calculations for a 3500-atom ZnTeO alloy. Isosurface plots (yellow) show the electron wavefunction squares for the bottom of the conduction band (left) and the top of the oxygen-induced band (right). The small grey dots are Zn atoms, the blue dots are Te atoms, and the red dots are oxygen atoms.

Credit: Berkeley Lab's Computing Sciences
The key to energy independence from petroleum, coal and other fossil fuels, could be tiny materials called nanostructures. At approximately 100,000 times finer than human hair, these structures maybe microscopic individually, but in groups of thousands, they could revolutionize solar-cell design by providing a cost-efficient resource for harvesting solar-energy.

To theoretically understand and simulate the energy harnessing potential of nanostructures, a team of researchers in the Berkeley Lab’s Computational Research Division (CRD) developed the Linear Scaling Three Dimensional Fragment (LS3DF) method. The computer algorithms in this method use a “divide-and-conquer” technique to efficiently gain insights into how nanostructures function in systems with 10,000 or more atoms.

By incorporating the correct chemical formulas into efficient computer programs, scientists can learn a lot about the structures and properties of molecules and solids.… I like to think of computers as chemistry’s ‘third leg.’ In most cases, computer simulations complement information obtained by chemical experiments, but in some cases it can predict unobserved phenomena,” says Dr. Lin-Wang Wang, a CRD computational material scientist and leader of the LS3DF project.

The developers of LS3DF are finalists in the Association for Computing Machinery’s (ACM) Gordon Bell Prize Competition, which recognizes outstanding achievement in high-performance computing applications. The winners will be announced on November 20, 2008 at the SC08 Conference in Austin, Tex.

According to Wang, traditional methods for calculating the energy potential of nanostructure systems containing 10,000 or more atoms can be very time consuming and resource intensive. Because these techniques calculate the entire structure as a whole system, the compute time, disk space and memory required to determine the energy potential of these structures grows to the third power of the system’s size. That means calculating a 1000-atom system will be a thousand times more expensive than calculating a 100-atom system.

He notes that LS3DF offers a more efficient way for calculating energy potential because it is based on the observation that the total energy of a large nanostructure system can be broken down into small pieces, and each piece can be calculated separately. Wang refers to this technique as “divide-and-conquer.”

The total energy of the large system has two components: electrostatic energy and quantum mechanical energy. To determine the structure’s total quantum mechanical energy, the LS3DF method breaks the entire structure into small fragments, applies its algorithm to each individual piece, and then combines the results of the pieces to get a total for the whole system. Scientists say that under the traditional density functional theory methods, the quantum mechanical energy calculation typically requires the most compute time and resources. By breaking up the big problem into small pieces, LS3DF can solve it a lot more quickly and efficiently, making the computational cost proportional to the total number of the atoms in the system.

Meanwhile, the electrostatic energy of large-scale nanostructure systems is not as resource intensive to solve. Scientists calculate this classical energy by looking at the whole system, which may contain tens of thousands of atoms. This problem is solved separately from the quantum mechanic energy. In the end, both energy results are combined to get the structure’s total energy potential.

When team members tested the LS3DF method on supercomputers at the Department of Energy’s (DOE) National Energy Scientific Research Center (NERSC) in Oakland, Calif, National Center for Computational Sciences (NCCS) at Oak Ridge National Laboratory in Oak Ridge, Tenn., and Argonne Leadership Computing Facility in Argonne, Ill., they found that the LS3DF method can work hundreds to thousands of times faster than traditional density functional theory calculations for systems with tens of thousands of atoms, and yielded essentially the same results.

The core of LS3DF is a novel patching scheme that cancels out the artificial boundary effects caused by dividing the system into smaller fragments,” says Wang. “This cancellation is what gets us the same results as the traditional method.”

Because LS3DF scales almost perfectly with the number of compute cores, it is the first electronic structure code that runs efficiently on computer systems with tens to hundreds of thousands of cores. On 17,280 cores of the dual-core Cray XT4 (Franklin) at NERSC, LS3DF achieved 32 Tflop/s or 32% of the peak floating-point performance of the machine. On 30,720 cores of the quad-core Cray XT4 (Jaguar) at NCCS, LS3DF reached 60 Tflop/s or 23% of the theoretical peak. In a later run on the IBM BlueGene/P system (Intrepid) at Argonne, the code achieved 107.5 Tflop/s on 131,072 cores, or 24.2% of peak.

Energy Independence from Fossil Fuels

Scientists agree that a fundamental understanding of nanostructure behaviors and properties could provide a solution for curbing our dependence on petroleum, coal, and other fossil fuels.

According to Wang, nanostructure systems are cheaper to produce than the crystal thin films used in current solar cell designs, and offer the same material purity. In addition, nanostructures are extremely versatile. They can act as electrodes to carry electric currents, or active materials that absorb sunlight and convert it to electricity.

One type of nanostructure, called quantum dots, actually changes color with size. Scientists say this color, or band gap, affects the type of light that the structure absorbs, which will be very useful for designing solar-cells.

We still don't quite understand how the electron moves around in a nanostructure, and how such properties depend on the size, geometry, composition, and surface passivations … Understanding such dependence will allow us to design nanostructures for desired applications, and LS3DF can help us to understand and predict these properties with computers,” says Wang.

Other authors on the Gorden Bell paper include the Berkeley Lab’s David H. Bailey, Zhao, Byounghak, Zhengji Lee, Juan Meza, Hongzhang Shan, and Erich Strohmaier.

Source: Berkeley Lab's Computing Sciences / Linda Vu

AddThis Social Bookmark Button

Scientific Frontline®
RSS Feeds

Scientific Frontline®
The Comm Center
The E.A.R.®
World News Report
Stellar Nights®
Cassini Gallery
Mars Gallery
Missions Gallery
Observatories Gallery
Observatories Gallery
Space Weather Alerts
Events
Directors Chair

Scientific Frontline®
Is supported in part by
Readers Like You”
 
Electron Pairs Precede High-Temperature Superconductivity New Generator Produces AC Current by Stretching Wires ESnet4 Helps Researchers Seeking the Origins of Matter Navigate Back or Forward Through Technology News, Related Page or Pick an Article From The News Ticker.


Scientific Frontline®, Stellar Nights®, E.A.R.®, and Environmental Awareness Report®”
Are Registered Trademarks of the
Online Publication of the SFL ORG. Educational News Network
Oklahoma City, Oklahoma USA
A Not-for-Profit Educational News Service
© 2005 - 2008 All Rights Reserved


Home | Comm. Center | Science | Earth Science | Space | Space Weather Center | Aviation | Technology | Galleries | About Us | Contact Us | Site Map | FAQ