https://en.m.wikipedia.org/wiki/Muon

https://en.m.wikipedia.org/wiki/Muon-catalyzed_fusion

https://en.m.wikipedia.org/wiki/Rydberg_atom

https://en.m.wikipedia.org/wiki/Rydberg_formula

https://en.m.wikipedia.org/wiki/Rydberg_matter

https://en.m.wikipedia.org/wiki/Rydberg_molecule

https://en.m.wikipedia.org/wiki/Rydberg_state

https://en.m.wikipedia.org/wiki/Rydberg_constant

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Rydberg matter, is an exotic phase of matter formed by Rydberg atoms

Rydberg states, an atom or molecule electronically excited states with energies that converge on an ionic state with an ionization energy.

Rydberg constant, a constant related to atomic spectra

Rydberg formula, a formula describing wavelengths

Rydberg atom, an excited atomic state

Rydberg molecule, an electronically excited chemical substance

Rydberg unit of energy (symbol Ry), derived from the Rydberg constant

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https://en.m.wikipedia.org/wiki/Exotic_atom

https://en.m.wikipedia.org/wiki/Hydrogen-like_atom

https://en.m.wikipedia.org/wiki/Dihydrogen_cation