https://doi.org/10.1351/goldbook.R05430
Atomic fundamental physical constant \(R_{\infty} = \frac{E_{h}}{2\ h\ c_{0}} = 1.097\ 373\ 1534\ (13)\times 10^{7}\ \rm{m}^{-1}\), where \(E_{h}\) is the Hartree energy, \(h\) the Planck constant, and \(c_{0}\) the speed of light.