scipp.constants#

Physical and mathematical constants with units. This module a wrapper around scipy.constants and requires the scipy package to be installed.

Mathematical constants:

pi

Pi

golden

Golden ratio

golden_ratio

Golden ratio

Physical constants:

c

speed of light in vacuum

speed_of_light

speed of light in vacuum

mu_0

the magnetic constant \(\mu_0\)

epsilon_0

the electric constant (vacuum permittivity), \(\epsilon_0\)

h

the Planck constant \(h\)

Planck

the Planck constant \(h\)

hbar

\(\hbar = h/(2\pi)\)

G

Newtonian constant of gravitation

gravitational_constant

Newtonian constant of gravitation

g

standard acceleration of gravity

e

elementary charge

elementary_charge

elementary charge

R

molar gas constant

gas_constant

molar gas constant

alpha

fine-structure constant

fine_structure

fine-structure constant

N_A

Avogadro constant

Avogadro

Avogadro constant

k

Boltzmann constant

Boltzmann

Boltzmann constant

sigma

Stefan-Boltzmann constant \(\sigma\)

Stefan_Boltzmann

Stefan-Boltzmann constant \(\sigma\)

Wien

Wien displacement law constant

Rydberg

Rydberg constant

m_e

electron mass

electron_mass

electron mass

m_p

proton mass

proton_mass

proton mass

m_n

neutron mass

neutron_mass

neutron mass

In addition to the above variables, scipp.constants also contains the 2018 CODATA recommended values [CODATA2018] database containing more physical constants. The database is accessed using scipp.constants.physical_constants().

CODATA2018

CODATA Recommended Values of the Fundamental Physical Constants 2018. https://physics.nist.gov/cuu/Constants/

Functions

physical_constants(key[, with_variance])

Returns the CODATA recommended value with unit of the requested physical constant.