Featured Research

from universities, journals, and other organizations

Algorithm Advance Produces Quantum Calculation Record

Date:
March 21, 2006
Source:
National Institute of Standards and Technology
Summary:
Two theoreticians from the National Institute of Standards and Technology (NIST) and Indiana University (IU) have published the most accurate values yet for fundamental atomic properties of a molecule -- values calculated from theory alone. They announced a new high-precision calculation of the energy required to pull apart the two atoms in a hydrogen molecule.

Two theoreticians from the National Institute of Standards and Technology (NIST) and Indiana University (IU) have published the most accurate values yet for fundamental atomic properties of a molecule--values calculated from theory alone.

In a recent paper,* James Sims of NIST and Stanley Hagstrom of IU announced a new high-precision calculation of the energy required to pull apart the two atoms in a hydrogen molecule (H2). Accurate to 1 part in 100 billion, these are the most accurate energy values ever obtained for a molecule of that size, 100 times better than the best previous calculated value or the best experimental value. Their results are intrinsically interesting to astronomers studying galactic clouds of hydrogen, and to anyone else doing precision hydrogen spectroscopy, but the methods they used are perhaps equally important.

The calculation requires solving an approximation of the Schrφdinger equation, one of the central equations of quantum mechanics. It can be approximated as the sum of an infinite number of terms, each additional term contributing a bit more to the accuracy of the result. For all but the simplest systems or a relative handful of terms, however, the calculation rapidly becomes impossibly complex. While very precise calculations have been done for systems of just three components such as helium (a nucleus and two electrons), Sims and Hagstrom are the first to reach this level of precision for H2 with two nuclei and two electrons. Their calculations were carried out to 7,034 terms.

To make the problem computationally practical, Sims and Hagstrom merged two earlier algorithms for these calculations--one which has advantages in ease of calculation, and one which more rapidly achieves accurate results--into a hybrid with some of the advantages of both. They also developed improved computer code for a key computational bottleneck (high-precision solution of the large-scale generalized matrix eigenvalue problem) using parallel processing. The final calculations were run on a 147-processor parallel cluster at NIST over the course of a weekend--on a single processor it would have taken close to six months.

* J. Sims and S. Hagstrom. 2006. High precision variational calculations for the Born-Oppenheimer energies of the ground state of the hydrogen molecule. The Journal of Chemical Physics, 124, 094101 (published online on March 1).

 


Story Source:

The above story is based on materials provided by National Institute of Standards and Technology. Note: Materials may be edited for content and length.


Cite This Page:

National Institute of Standards and Technology. "Algorithm Advance Produces Quantum Calculation Record." ScienceDaily. ScienceDaily, 21 March 2006. <www.sciencedaily.com/releases/2006/03/060320215143.htm>.
National Institute of Standards and Technology. (2006, March 21). Algorithm Advance Produces Quantum Calculation Record. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2006/03/060320215143.htm
National Institute of Standards and Technology. "Algorithm Advance Produces Quantum Calculation Record." ScienceDaily. www.sciencedaily.com/releases/2006/03/060320215143.htm (accessed April 23, 2014).

Share This



More Computers & Math News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

High Court to Hear Dispute of TV Over Internet

High Court to Hear Dispute of TV Over Internet

AP (Apr. 22, 2014) — The future of Aereo, an online service that provides over-the-air TV channels, hinges on a battle with broadcasters that goes before the U.S. Supreme Court on Tuesday. (April 22) Video provided by AP
Powered by NewsLook.com
Aereo Takes on Broadcast TV Titans in Supreme Court Today

Aereo Takes on Broadcast TV Titans in Supreme Court Today

TheStreet (Apr. 22, 2014) — Aereo heads to the Supreme Court today to fight for its right to stream broadcast TV over the Internet -- against broadcasters who say the start-up infringes upon copyright law. TheStreet Deputy Managing Editor Leon Lazaroff explains the importance of the case in the TV industry and details what the outcome of it could mean for broadcasters and for cloud storage services -- as Aereo allows its subscribers to not just watch live TV shows but also store content to a DVR in the cloud. Video provided by TheStreet
Powered by NewsLook.com
Lytro Introduces 'Illum,' A Professional Light-Field Camera

Lytro Introduces 'Illum,' A Professional Light-Field Camera

Newsy (Apr. 22, 2014) — The light-field photography engineers at Lytro unveiled their next innovation: a professional DSLR-like camera called "Illum." Video provided by Newsy
Powered by NewsLook.com
Netflix To Raise Prices For New Subscribers

Netflix To Raise Prices For New Subscribers

Newsy (Apr. 21, 2014) — Netflix executives say they don't think a $1 or $2 price hike will hurt the service, and they have their sites set on overtaking HBO. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins