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NIST scientists are actively developing new algorithms for extremely high-accuracy computation of non-relativistic eigenstates of few-electron atomic systems.


The numerical solution of the multi-particle Schrodinger equation describing atomic systems remains a challenging for computational physics. ITL scientists are in the forefront of this field with respect to extremely high-accuracy computation of non-relativistic eigenstates of few electron systems.

Major Accomplishments

  • November 2009. NIST's James Sims and IU's 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 behavior, but the success of the method the team employed has implications that go beyond lithium alone. The work appeared in Physical Review A. (paper)
Created January 5, 2010, Updated June 2, 2021