Free electron g factor.

value = gfree
[value,sigma] = gfree

gfree returns the g value of the free electron in value and the standard deviation in sigma (if two output arguments are specified).

The value and its standard deviation are taken from the 2008 measurement published in

• D.Hanneke, S.Fogwell, G.Gabrielse,
  New Measurement of the Electron Magnetic Moment and the Fine Structure Constant,
  Phys.Rev.Lett. 100, 120801 (2008).

amu, avogadro, barn, bmagn, bohrrad, boltzm, clight, echarge, emass, faraday, hartree, molgas, nmagn, nmass, planck, pmass, rydberg