Rydberg constant
m⁻¹
The Rydberg constant gives the wavenumbers of hydrogen's spectral lines through the Rydberg formula. It is exact in the revised SI because it is defined in terms of other exact constants.
Used in
- Rydberg formula for hydrogen spectral lines 1/λ = R(1/n₁² − 1/n₂²)
- Precision tests of atomic theory
Source: SI defining constants / CODATA 2018