Atomic radii (density cutoff)

Many references give table of atomic radii. Sometimes in text books and other sources, the rather vague term "atomic radius" is not defined and in such cases it is therefore not clear what the values actually mean. The values given here for atomic radius are calculated values using methods outlined in reference 1.

The definition of this form of atomic radius is based upon the electron density of isolated atoms in the atomic ground state and is the average distance from the nucleus where the electron density falls to 0.001 electrons per bohr3. These radii are derived using relativistic all-electron density functional theory calculations. They offer a systematic quantitative measure of the sizes of non-interacting atoms (commonly invoked in the rationalisation of chemical bonding, structure, and other properties. These atomic radii correlate well with van der Waals radii derived from crystal structures.

Image showing periodicity of the chemical elements for atomic radii (density cutoff) in a bar chart.
Image showing periodicity of the chemical elements for atomic radii (density cutoff) in a bar chart.

Units

pm

Notes

None

Select from the following links to see visual periodicity representations for atomic radii, covalent radii, and van der Waals radii. Ionic radii are also available.

Literature sources

  1. M. Rahm, R. Hoffmann, and N.W. Ashcroft, Chem. Eur. J. 2016, 22, 14625-14632.
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*Lanthanoids *
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