Atomic fundamental physical constant, \(\alpha =\frac{\mu _{0}\ e^{2}\ c_{0}}{2\ h} = 7.297\ 353\ 08\ \left(33\right)\times 10^{-3}\), where \(\mu _{0}\) is the permeability of vacuum, \(e\) the elementary charge, \(h\) the Planck constant, and \(c_{0}\) the speed of light.