https://doi.org/10.1351/goldbook.H02748
Atomic fundamental physical constant used as @A00504@ of energy: \(E_{\text{h}}=\frac{\mathrm{\hslash }^{2}}{m_{\text{e}}\ a_{0}^{2}} = 4.359\ 7482(26)\times 10^{-18}\ \text{J}\), where \(\mathrm{\hslash}\) is the @P04685@ divided by \(2\ \pi \), \(m_{\text{e}}\) the @E02008@ and \(a_{0}\) the @B00693@.
Source:
CODATA Bull. 1986, 63, 1 [Terms] [Book]