ConstantID

Electron magnetic moment to Bohr magneton ratio

Atomic & nuclearMeasured

μe/μB = −1.001 159 652 180 46(18)

Value
−1.001 159 652 180 46
Standard uncertainty
1.8 × 10−13
Relative uncertainty
1.8 × 10−13 (0.18 parts per trillion)
Status
Measured
Symbol
μe/μB
Source
CODATA 2022 via NIST · NIST entry

Use in a calculation

# electron magnetic moment to Bohr magneton ratio, CODATA 2022 (NIST)
electron_magnetic_moment_to_bohr_magneto = -1.00115965218046  # standard uncertainty 1.8e-13

# SciPy: scipy.constants.physical_constants['electron mag. mom. to Bohr magneton ratio']

What it is

The magnetic moment of the electron, the lightest charged particle and the carrier of electric current in metals, expressed in Bohr magnetons.

How the value changed, 1998–2022

Each point is one CODATA adjustment, plotted as its difference from the 2022 value; the bars show one standard uncertainty (an arrowhead means the bar runs off the chart).

electron magnetic moment to Bohr magneton ratio: CODATA values 1998–2022 relative to the 2022 value, in parts per trillion, with one-standard-uncertainty bars−10−50+5+10parts per trillion1998200220062010201420182022

Relative uncertainty

electron magnetic moment to Bohr magneton ratio: relative standard uncertainty in each CODATA adjustment, logarithmic scale10⁻¹³10⁻¹²10⁻¹¹1998200220062010201420182022
CODATAValue (uncertainty)Relative uncertaintyChange from previous
2022−1.001 159 652 180 46(18)1.8 × 10−13 +4.6 σ of 2018
2018−1.001 159 652 181 28(18)1.8 × 10−13 −1.4 σ of 2014
2014−1.001 159 652 180 91(26)2.6 × 10−13 −0.6 σ of 2010
2010−1.001 159 652 180 76(27)2.7 × 10−13 +0.5 σ of 2006
2006−1.001 159 652 181 11(74)7.4 × 10−13 +1.3 σ of 2002
2002−1.001 159 652 1859(38)3.8 × 10−12 +0.2 σ of 1998
1998−1.001 159 652 1869(41)4.1 × 10−12

“Change from previous” is the shift in the value divided by the standard uncertainty of the previous adjustment. Earlier values are converted into the current unit where NIST changed it (for example J s to J Hz⁻¹).

Related constants

Atomic & nuclear −e/me Electron charge to mass quotient −1.758 820 008 38(55) × 1011 C kg−1 Atomic & nuclear μe/μd Electron-deuteron magnetic moment ratio −2143.923 4921(56) Atomic & nuclear me/md Electron-deuteron mass ratio 2.724 437 107 629(47) × 10−4 Atomic & nuclear ge Electron g-factor −2.002 319 304 360 92(36) Atomic & nuclear γe Electron gyromagnetic ratio 1.760 859 627 84(55) × 1011 s−1 T−1 Atomic & nuclear γe/2π Electron gyromagnetic ratio in MHz/T 28 024.951 3861(87) MHz T−1 Atomic & nuclear me/mh Electron-helion mass ratio 1.819 543 074 649(53) × 10−4 Atomic & nuclear μe Electron magnetic moment −9.284 764 6917(29) × 10−24 J T−1