* Astronomy

Scientists at the National Institute of Standards and Technology (NIST) and Indiana University (IU) have determined the most accurate values ever for a fundamental property of the element lithium using a novel approach that may permit scientists to do the same for other atoms in the periodic table.
NISTs James Sims and IUs Stanley Hagstrom have calculated four excitation energies for the lithium atom approximately 100 times more accurately than any previous calculations or experimental measurements. Precise determination of excitation energy - the amount necessary to raise an atom from a base energy level to the next higher - has intrinsic value for fundamental research into atomic behaviour, but the success of the method the team employed has implications that go beyond lithium alone.
The theorists have overcome major computational and conceptual hurdles that for decades have prevented scientists from using quantum mechanics to predict electron excitation energies from first principles. Sims first proposed in the late 1960s that such a quantum approach could be possible, but its application to anything more than two electrons required a fiendishly difficult set of calculations that, until recently, was beyond the capacity of even the worlds fastest computers. In 2006 the team used a novel combination of algorithms, extended precision computing and the increase in power brought about by parallel computing to calculate the most accurate values ever for a simple, two-electron hydrogen molecule.

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