Tiesinga, E.
(2023),
Units and constants, Handbook of Atomic, Molecular, and Optical physics, Springer Verlag, New York, NY
(Accessed April 1, 2026)
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Units and constants
Published
Author(s)
Abstract
We describe atomic and natural units relevant for the atomic, molecular, and optical physics described in this book. For nonrelativistic models of atoms and molecules absorbing and emitting photons atomic units are appropriate. That is energies and lengths are expressed in terms of the Hartree energy and Bohr radius, respectively. Relativistic models are required for precision quantum electrodynamics-based determinations of energy levels of hydrogen and other light atoms and molecules. Natural units are then most appropriate and energies and length are expressed in the rest energy of the electron and the reduced Compton wavelength, respectively. Finally, we present values for an abbreviated list of fundamental constants taken from the CODATA adjustment of fundamental constants based on data published or made available before end of 2018.Citation
Handbook of Atomic, Molecular, and Optical physics
Publisher Info
Springer Verlag, New York, NY
Pub Type
Book Chapters
Keywords
units, fundamental constants
Citation
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Created July 3, 2023, Updated March 31, 2026