ConstantID

Shielding difference of d and p in HD

Atomic & nuclearMeasured

σdp = 1.987 70(10) × 10−8

Value
1.987 70 × 10−8
Standard uncertainty
1 × 10−12
Relative uncertainty
5.0 × 10−5 (50 parts per million)
Status
Measured
Symbol
σdp
Source
CODATA 2022 via NIST · NIST entry

Use in a calculation

# shielding difference of d and p in HD, CODATA 2022 (NIST)
shielding_difference_of_d_and_p_in_hd = 1.9877e-8  # standard uncertainty 1e-12

# SciPy: scipy.constants.physical_constants['shielding difference of d and p in HD']

What it is

The difference between the magnetic shielding of the deuteron and of the proton in the HD molecule. It lets measurements in HD be turned into the ratio of the bare deuteron and proton magnetic moments.

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).

shielding difference of d and p in HD: CODATA values 1998–2022 relative to the 2022 value, in parts per thousand, with one-standard-uncertainty bars−30−20−100+10+20+30parts per thousand1998200220062010201420182022

Relative uncertainty

shielding difference of d and p in HD: relative standard uncertainty in each CODATA adjustment, logarithmic scale10⁻⁵10⁻⁴10⁻³1998200220062010201420182022
CODATAValue (uncertainty)Relative uncertaintyChange from previous
20221.987 70(10) × 10−85.0 × 10−5 −16.1 σ of 2018
20182.0200(20) × 10−89.9 × 10−4

“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 a0 Bohr radius 5.291 772 105 44(82) × 10−11 m Atomic & nuclear re Classical electron radius 2.817 940 3205(13) × 10−15 m Atomic & nuclear λC Compton wavelength 2.426 310 235 38(76) × 10−12 m Atomic & nuclear α Fine-structure constant 7.297 352 5643(11) × 10−3 Atomic & nuclear Eh Hartree energy 4.359 744 722 2060(48) × 10−18 J Atomic & nuclear Eh Hartree energy in eV 27.211 386 245 981(30) eV Atomic & nuclear α−1 1/α 137.035 999 177(21) Atomic & nuclear πℏ/me Quantum of circulation 3.636 947 5467(11) × 10−4 m2 s−1