FUNDAMENTAL
PHYSICAL
CONSTANTS
- Planck constant h
- 6.6260755·10-34 J·s
- h / (2 π) = 1.05457266·10-34 J·s
- Boltzmann constant kB
- 1.380658·10-23 J/K ( = 8.617385·10-5 eV/K )
- Elementary charge e
- 1.60217733·10-19 C
- Avogadro number NA
- 6.0221367·1023 particles/mol
- Speed of light c
- 2.99792458·108 m/s
- Permeability of vacuum μ0
- μ0 = 4 π ·10-7 T2·m3/J
- 12.566370614·10-7 T2·m3/J
- Permittivity of vacuum ε0
- ε0 = 1 / (μ0 c2)
- 8.854187817·10-12 C2/J·m
- Fine structure constant α
- 1 / 137.0359895
- Electron rest mass me
- 9.1093897·10-31 kg
- Proton rest mass mp
- 1.6726231·10-27 kg
- Neutron rest mass mn
- 1.6749286·10-27 kg
- Bohr magneton μB
- μB = e h / (4 π me)
- 9.2740154·10-24 J/T
- Nuclear magneton μN
- μN = e h / (4 π mp)
- 5.0507866·10-27 J/T
- Free electron g factor ge
- 2.002319304386
- Free electron gyromagnetic ratio Γe
- Γe = 2 π ge μB / h
- 1.7608592·1011 1/s·T
- Γe / (2 π) = 28.024944 GHz/T
- Electron magnetic moment
μe
- μe = -(1/2) ge μB
- -9.2847701·10-24 J/T
- Proton gyromagnetic ratio (H2O) Γp
- 2.67515255·108 1/s·T
- Γp / (2 π) = 42.576375 MHz/T
- Proton magnetic moment
μp
- 1.41060761·10-26 J/T
- Proton-electron ratios
- mp / me = 1836.152701
- μe / μp = 658.2106881
- Γe / Γp = 658.2275841 (protons in water)
- Charge-to-mass ratio for the electron e / me
- 1.75880·1011 C/kg
- Atomic mass unit amu
- 1.66054·10-27 kg
- Bohr radius a0
- 5.29177·10-11 m
- Electron radius re
- 2.81792·10-15 m
- Gas constant R
- R = NA kB
- 8.31451 m2·kg/s2·K·mol
- Molar volume Vmol
- 22.41383 m3/kmol
- Faraday constant F
- F = NA e
- 9.64846·104 C/mol
- Proton g factor (Landé factor) gH
- 5.585
- Gravitational constant G
- Acceleration due to gravity g
- 9.80665 m/s2
- Compton wavelength of the electron λc
- λc = h / (me c)
- 2.42631·10-12 m
FURTHER
USEFUL
CONSTANTS
- Atomic energy unit Hartree
- 1 Hartree = e2 / (4 π ε0 a0)
- 1 Hartree = 2.625501·106 J/mol (approx. 627.5 kcal/mol)
USEFUL
CONVERSION
FACTORS
NMR (Nuclear Magnetic Resonance)
- Proton Larmor frequency
- νp = Γp / (2 π) B
- νp = 42.5764 MHz/T (H2O)
EPR (Electron Paramagnetic Resonance, ESR)
(Note that the use of brackets [ ] in the following expressions
is not in accordance with standards which require the use of a slash,
e.g. A/MHz.)
- Electron Larmor frequency
- νe = Γe / (2 π) (g / ge) B
- νe [GHz] = 13.9962 g B [T]
- g = 0.07144775 νe [GHz] / B [T]
- g = 3.04199 νe [GHz] / νp [MHz]
- B [T] = 0.0234872 νp [MHz]
- Conversion of Units
- 1 G = 0.1 mT
- 1 T = 10 kG
- 1 mT = 10 G
- A [MHz] = 2.80249 (g / ge) A [G]
- A [MHz] = 28.0249 (g / ge) A [mT]
- A [MHz] = 13.9962 g A [mT]
- A [MHz] = 2.99792·104 A [cm-1]
- A [cm-1] = 0.333564·10-4 A [MHz]
- A [cm-1] = 4.66863·10-4 g A [mT]
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