Atomic unit of charge density
UnitsMeasured
= 1.081 202 386 77(51) × 1012 C m−3
- Value
- 1.081 202 386 77 × 1012 C m−3
- Standard uncertainty
- 510 C m−3
- Relative uncertainty
- 4.7 × 10−10 (472 parts per trillion)
- Status
- Measured
- Symbol
- Source
- CODATA 2022 via NIST · NIST entry
Use in a calculation
Plain
LaTeX
Python
# atomic unit of charge density, CODATA 2022 (NIST)
atomic_unit_of_charge_density = 1.08120238677e12 # C m^-3, standard uncertainty 510
# SciPy: scipy.constants.physical_constants['atomic unit of charge density']What it is
The unit of charge density 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 | 1.081 202 386 77(51) × 1012 | 4.7 × 10−10 | +4.5 σ of 2018 |
| 2018 | 1.081 202 384 57(49) × 1012 | 4.5 × 10−10 | +1.1 σ of 2014 |
| 2014 | 1.081 202 3770(67) × 1012 | 6.2 × 10−9 | +1.6 σ of 2010 |
| 2010 | 1.081 202 338(24) × 1012 | 2.2 × 10−8 | +1.4 σ of 2006 |
| 2006 | 1.081 202 300(27) × 1012 | 2.5 × 10−8 | −0.2 σ of 2002 |
| 2002 | 1.081 202 317(93) × 1012 | 8.6 × 10−8 | +0.7 σ of 1998 |
| 1998 | 1.081 202 285(43) × 1012 | 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).