`mu_B = 13.99624555 * 10^9 (Hz)/T`

1.39962455E+10

Bohr Magneton over Planck Constant (Hz/T)

The Bohr Magneton is both a physical constant and the natural unit for expressing an electron magnetic dipole moment. The Bohr Magneton (symbol: `mu_B`) is the magnitude of the magnetic dipole moment of an orbiting electron with an orbital angular momentum of one reduced Planck constant.  This constant, the Borh Magneto over the Planck Constant, (`mu_B`/h) is expressed in Hertz per Tesla.

Notes

This constant, the Bohr Magneton over Planck Constant, `mu_B`/h, is specified with standard uncertainty (standard deviation) of 0.00000031 x `10^9` Hz/T

See Uncertainty of Measurement Results, a discussion provided by NIST of the application of uncertainty to the documented constants.