Physical Constants
Overview
Several packages collect physical constants.
Packages
PhysicalConstants.jl
Collection of fundamental physical constants with uncertainties. It supports arbitrary-precision constants.
This is part of the JuliaPhysics organization. It contains data from 3 datasets[1] each as it's own submodule: PhysicalConstants.CODATA2014, PhysicalConstants.CODATA2018, PhysicalConstants.CODATA2022.
List of constants 24: CODATA2022.
| Long name | Short | Value | Unit |
|---|---|---|---|
| AtomicMassConstant | m_u | 1.66053906892e-27 | kg |
| AvogadroConstant | N_A | 6.02214076e23 | mol^-1 |
| BohrMagneton | μ_B | 9.2740100657e-24 | J T^-1 |
| BohrRadius | a_0 | 5.29177210544e-11 | |
| BoltzmannConstant | k_B | 1.380649e-23 | J K^-1 |
| CharacteristicImpedanceOfVacuum | Z_0 | 376.730313412 | |
| ElectronMass | m_e | 9.1093837139e-31 | kg |
| ElementaryCharge | e | 1.602176634e-19 | |
| FineStructureConstant | α | 0.0072973525643 | |
| MolarGasConstant | R | 8.31446261815324 | J K^-1 mol^-1 |
| NeutronMass | m_n | 1.67492750056e-27 | kg |
| NewtonianConstantOfGravitation | G | 6.6743e-11 | m^3 kg^-1 s^-2 |
| PlanckConstant | h | 6.62607015e-34 | J s |
| ProtonMass | m_p | 1.67262192595e-27 | kg |
| ReducedPlanckConstant | ħ | 1.0545718176461565e-34 | J s |
| RydbergConstant | R_∞ | 1.0973731568157e7 | m^-1 |
| SpeedOfLightInVacuum | c_0 | 2.99792458e8 | m s^-1 |
| StandardAccelerationOfGravitation | g_n | 9.80665 | m s^-2 |
| StandardAtmosphere | atm | 101325.0 | Pa |
| StefanBoltzmannConstant | σ | 5.6703744191844294e-8 | W K^-4 m^-2 |
| ThomsonCrossSection | σ_e | 6.6524587051e-29 | m^2 |
| VacuumElectricPermittivity | ε_0 | 8.8541878188e-12 | F m^-1 |
| VacuumMagneticPermeability | μ_0 | 1.25663706127e-6 | N A^-2 |
| WienFrequencyDisplacementLawConstant | b′ | 5.878925757646825e10 | Hz K^-1 |
| WienWavelengthDisplacementLawConstant | b | 0.0028977719551851727 | K m |
PhysicalConstants.jl was started in 2018 by giordano. He is still the main contributor with a few commits by 6 other developers[1].
PeriodicTable.jl
Periodic Table for Julians! 🔥
This is part of the JuliaPhysics organization. Use this i fyou just need standard data on elements: name, appearance, atomicmass, boil, category, color, density, discoveredby, melt, molarheat, namedby, number, period, phase, source, spectral_img, summary, symbol, xpos, ypos, shells.
PeriodicTable.jl was started in 2018 by rahulkp220. Since then, it has mainly been maintained by carstenbauer with contributions from 9 others[1].
Mendeleev.jl
A Julia package for accessing chemical elements data.
This contains (almost) all the same data as PeriodicTable.jl plus some more: https://eben60.github.io/Mendeleev.jl/elements_data_fields/. Use this if you need more data on the elements.
Mendeleev.jl was started in 2022 by Eben60 who is also the top 3 contributor to PeriodicTable.jl. It has only had few updates since 2022 and not by others[1].
IsotopeTable.jl
Table of Isotopes for Julians. Interoperable with
PeriodicTable.jl
IsotopeTable.jl was done in 2022 by Gregstrq[1]. Use this if you need more precise isotope data.
Unitful.jl
The Unitful.jl package also contains 19 physical constants in this section:
| Const | Value | Description |
|---|---|---|
| G | 6.674,30 × 10^-11 m^3 / (kg × s^2) | universal gravitational constant |
| Na | 6.022,140,76 × 10^23 / mol. | Avogadro's constant |
| R | Na × k | the molar gas constant, |
| R∞ | 1.097,373,156,8160 × 10^-7 / m | Rydberg constant, |
| Z0 | μ0 × c | impedance of free space |
| c0 | 2.997,924,58 × 10^8 m/s | speed of light in a vacuum |
| gn | 9.806,65 m / s^2 | nominal acceleration due to gravity |
| h | 6.626,070,15 × 10^-34 J × s | Planck's constant |
| k | 1.380,649 × 10^-23 J / K | Boltzmann constant |
| me | 9.109,383,7015 × 10^-31 kg | rest mass of an electron |
| mn | 1.674,927,498,04 × 10^-27 kg | rest mass of a neutron |
| mp | 1.672,621,923,69 × 10^-27 kg | rest mass of a proton |
| q | 1.602,176,634 × 10^-19 C | charge of a single electron |
| ħ | h / 2π. | reduced Planck constant |
| Φ0 | h / (2 × q) | superconducting magnetic flux quantum |
| ε0 ϵ0 | 1 / (μ0 × c^2) | vacuum permittivity constant |
| μ0 | 4π × 10^-7 H / m | vacuum permeability constant |
| μB | q × ħ / (2 × me) | Bohr magneton |
| σ | π^2 × k^4 / (60 × ħ^3 × c^2) | Stefan-Boltzmann constant |
Those from PhysicalConstants.jl that are missing here are:
Bohr Radius
Standard atmospheric pressure
Fine Structure Constant
Thomson Cross Section
Wien Frequency Displacement Law Constant
Wien Wavelength Displacement Law Constant
The unique one here is:
Superconducting magnetic flux quantum
Unitful.jl was started in 2016 by ajkeller34. It is currently mainly maintained by sostock and has contributions from 76 developers[1].
Star History
| [1] | By 2025-07-15. |
Last modified: July 16, 2025. Built with Franklin.jl