sqrt2Rh

sqrt2Rh refers to the square root of twice the hydrogen Rydberg constant, written as sqrt(2R_h). The symbol R_h denotes the Rydberg constant for hydrogen, a fundamental quantity that sets the scale for hydrogenic spectral lines. In the Rydberg formula for hydrogen, 1/λ = R_h (1/n1^2 − 1/n2^2), where λ is the wavelength of emitted or absorbed light. The precise numerical value of R_h depends on the definition used (for example, whether reduced mass corrections are included), but it is commonly given as approximately 1.097373156×10^7 m^−1.

Taking the square root of twice this constant yields a derived quantity with units of m^−1/2. Numerically, with R_h ≈ 1.097×10^7 m^−1, sqrt(2R_h) ≈ sqrt(2.194×10^7) ≈ 4.68×10^3 m^−1/2. The result is not a standard physical constant with a widely recognized interpretation; rather, it is a mathematical construct that may appear in particular algebraic manipulations or model derivations where a term involving sqrt(2R_h) emerges.

Because sqrt(2R_h) does not correspond to a named physical constant, its use is typically confined to specific theoretical or computational contexts rather than broad physical interpretation. It is most meaningful to understand it in relation to the Rydberg constant and the hydrogen spectral formula, rather than as an independent, widely used quantity.

See also: Rydberg constant, hydrogen spectrum, Bohr model.