Atomic unit of electric quadrupole moment
UnitsMeasured
= 4.486 551 5185(14) × 10−40 C m2
- Value
- 4.486 551 5185 × 10−40 C m2
- Standard uncertainty
- 1.4 × 10−49 C m2
- Relative uncertainty
- 3.1 × 10−10 (312 parts per trillion)
- Status
- Measured
- Symbol
- Source
- CODATA 2022 via NIST · NIST entry
Use in a calculation
Plain
LaTeX
Python
# atomic unit of electric quadrupole moment, CODATA 2022 (NIST)
atomic_unit_of_electric_quadrupole_momen = 4.4865515185e-40 # C m^2, standard uncertainty 1.4e-49
# SciPy: scipy.constants.physical_constants['atomic unit of electric quadrupole mom.']What it is
The unit of electric quadrupole moment in the Hartree system of atomic units, where the electron mass, the elementary charge, ħ and 4πε₀ are all set to 1. Its value here is the SI equivalent of one atomic unit.
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).
Relative uncertainty
| CODATA | Value (uncertainty) | Relative uncertainty | Change from previous |
|---|---|---|---|
| 2022 | 4.486 551 5185(14) × 10−40 | 3.1 × 10−10 | −4.4 σ of 2018 |
| 2018 | 4.486 551 5246(14) × 10−40 | 3.1 × 10−10 | +1.4 σ of 2014 |
| 2014 | 4.486 551 484(28) × 10−40 | 6.2 × 10−9 | +1.5 σ of 2010 |
| 2010 | 4.486 551 331(99) × 10−40 | 2.2 × 10−8 | +2.4 σ of 2006 |
| 2006 | 4.486 551 07(11) × 10−40 | 2.5 × 10−8 | −0.4 σ of 2002 |
| 2002 | 4.486 551 24(39) × 10−40 | 8.7 × 10−8 | +1.3 σ of 1998 |
| 1998 | 4.486 551 00(18) × 10−40 | 4.0 × 10−8 |
“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).