#!/usr/bin/env python3
# -*- coding: utf-8 -*-
'''
This module provides Physical constants.
It was originally written by Herman J.C. Berendsen.
The data originates from the CODATA 2006 release.
See http://www.physics.nist.gov/PhysRefData/contents.html.
This could be replaced by scipy.constants in the future.
Example usage::
>>> import h5utils.constants.physcon as physcon
>>> physcon.help()
Available functions:
[note: key must be a string, within quotes!]
value(key) returns value (float)
sd(key) returns standard deviation (float)
relsd(key) returns relative standard deviation (float)
descr(key) prints description with units
Available global variables:
alpha, a_0, c, e, eps_0, F, G, g_e, g_p, gamma_p, h, hbar, k_B
m_d, m_e, m_n, m_p, mu_B, mu_e, mu_N, mu_p, mu_0, N_A, R, sigma, u
Available keys:
['alpha', 'alpha-1', 'amu', 'avogadro', 'bohrmagn', 'bohrradius', 'boltzmann', 'charge-e', 'conduct-qu', 'dirac', 'elec-const', 'faraday', 'gas', 'gfactor-e', 'gfactor-p', 'gravit', 'gyromagratio-p', 'josephson', 'lightvel', 'magflux-qu', 'magn-const', 'magnmom-e', 'magnmom-p', 'magres-p', 'mass-d', 'mass-d/u', 'mass-e', 'mass-e/u', 'mass-mu', 'mass-mu/u', 'mass-n', 'mass-n/u', 'mass-p', 'mass-p/u', 'nuclmagn', 'planck', 'ratio-me/mp', 'ratio-mp/me', 'rydberg', 'stefan-boltzm']
>>> physcon.value('lightvel')
299792458.0
>>> physcon.sd('lightvel')
0.0
>>> physcon.relsd('lightvel')
0.0
>>> physcon.descr('lightvel')
Description of lightvel :
Name: velocity of light in vacuum
Symbol (if avail.): c
Value: 299792458.0
Standard deviation: 0.0
Relative stdev: 0.0
value(sd) unit: 299 792 458(ex) m/s
Source: CODATA 2006
>>> physcon.get_c0()
299792458.0
'''
# physcon Physical constants
# Note: type physcon.help() (after import physcon)
# Copyright 2004, 2007 Herman J.C. Berendsen, <www.hjcb.nl/python>;
# email <herman@hjcb.nl>. The data originate from the CODATA 2006 release,
# see <http://www.physics.nist.gov/PhysRefData/contents.html>.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version. See <http://www.gnu.org/licenses/gpl.txt>
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
from math import pi
# define light velocity, because we need it in calculations
cloc = 299792458.
# dictionary of physical constants in SI units.
# Values CODATA 2006 http://www.physics.nist.gov/cuu/Constants/
# each item: [description (string), symbol (string), value (float), sd (float), relat. sd (float),
# value(sd) unit (string), source (string)]
all_dict = {'lightvel':['velocity of light in vacuum', 'c', cloc, 0., 0., '299 792 458(ex) m/s', 'CODATA 2006'],
'planck':["Planck's constant", 'h', 6.62606896e-34, 3.3e-41, 5.0e-8, '6.626 068 96(33) e-34 J s', 'CODATA 2006'],
'dirac':["Dirac's constant = h/(2 pi)", 'hbar', 1.054571628e-34, 5.3e-42, 5.0e-8, '1.054 571 628(53) e-34 J s', 'CODATA 2006 '],
'magn-const':['magnetic permeability of vacuum', 'mu_0', 4e-7*pi, 0., 0., '1.256 637 061... e-6 N A^-2', ''],
'elec-const':['dielectric permittivity of vacuum', 'eps_0', 1.e7/(4*pi*cloc*cloc), 0., 0., '8.854 187 817... e-12 F/m', ''],
'gravit':['Newton constant of gravitation', 'G', 6.67428e-11, 6.7e-15, 1.0e-4, '6.674 28(67) e-11 m^3 kg^-1 s^-2', 'CODATA 2006'],
'charge-e':['elementary charge', 'e', 1.60217653e-19, 1.4e-26, 8.5e-8, '1.602 176 53(14) e-19 C', 'CODATA 2006'],
'mass-e':['electron mass', 'm_e', 9.10938215e-31, 4.5e-38, 5.0e-8, '9.109 382 15(45) e-31 kg', 'CODATA 2006'],
'mass-e/u':['electron mass in u', 'm_e_u', 5.4857990943e-4, 2.3e-13, 4.2e-10, '5.485 799 0945(23) u', 'CODATA 2006'],
'mass-p':['proton mass', 'm_p', 1.672621637e-27, 8.3e-35, 5.0e-8, '1.672 621 637(83) e-27 kg', 'CODATA 2006'],
'mass-p/u':['proton mass in u', 'm_p_u', 1.00727646677, 1.0e-10, 1.0e-10, '1.007 276 466 77(10) u', 'CODATA 2006'],
'mass-n':['neutron mass', 'm_n', 1.674927211e-27, 8.4e-35, 5.0e-8, '1.674 927 211(84) e-27 kg', 'CODATA 2006'],
'mass-n/u':['neutron mass in u', 'm_n_u', 1.00866491597, 4.3e-10, 4.3e-10, '1.008 664 915 97(43) u', 'CODATA 2006'],
'mass-d':['deuteron mass', 'm_d', 3.34358320e-27, 1.7e-34, 5.0e-8, '3.343 583 20(17) e-27 kg', 'CODATA 2006'],
'mass-d/u':['deuteron mass in u', 'm_d_u', 2.013553212724, 7.8e-11, 3.9e-11, '2.013 553 212 724(78) u', 'CODATA 2006'],
'mass-mu':['muon mass', 'm_m', 1.88353130e-28, 1.1e-35, 5.6e-8, '1.883 531 30(11) e-28 kg', 'CODATA 2006'],
'mass-mu/u':['muon mass in u', 'm_m_u', 0.1134289256, 2.9e-9, 2.5e-8, '0.113 428 9256(29) u', 'CODATA 2006'],
'ratio-me/mp':['electron/proton mass ratio', 'ratio_memp', 5.4461702177e-4, 2.4e-13, 4.3e-10, '5.446 170 2177(24) e-4', 'CODATA 2006'],
'ratio-mp/me':['proton/electron mass ratio', 'ratio_mpme', 1836.15267247, 8.0e-7, 4.3e-10, '1836.152 672 47(80)', 'CODATA 2006'],
'amu':['unified atomic mass unit = 1/12 m(12C)', 'u', 1.660538782e-27, 8.3e-35, 5.0e-8, '1.660 538 782(83) e-27 kg', 'CODATA 2006'],
'avogadro':['Avogadro constant', 'N_A', 6.02214179e23, 3.0e16, 5.0e-8, '6.022 141 79(30) e23 mol^-1', 'CODATA 2006'],
'boltzmann':['Boltzmann constant', 'k_B', 1.3806504e-23, 2.4e-29, 1.7e-6, '1.380 6504(24) J/K', 'CODATA 2006'],
'gas':['molar gas constant = N_A k_B', 'R', 8.314472, 1.5e-5, 1.7e-6, '8.314 472(15) J mol^-1 K^-1', 'CODATA 2006'],
'faraday':['Faraday constant = N_A e', 'F', 96485.3399, 2.4e-3, 2.5e-8, '96 485.3399(24) C/mol', 'CODATA 2006'],
'bohrradius':['Bohr radius = 4 pi eps_0 hbar^2/(m_e e^2)', 'a_0', 5.2917720859e-11, 3.6e-20, 6.8e-10, '0.529 177 208 59(36) e-10 m', 'CODATA 2006'],
'magflux-qu':['magnetic flux quantum = h/(2 e)', 'Phi_0', 2.067833667e-15, 5.2e-23, 2.5e-8, '2.067 833 667(52) Wb', 'CODATA 2006'],
'conduct-qu':['conductance quantum = 2 e^2/h', 'G_0', 7.7480917004e-5, 5.3e-14, 6.8e-10, '7.748 091 7004(53) e-5 S', 'CODATA 2006'],
'josephson':['Josephson constant = 2 e/h', 'K_J', 4.83597891e14, 1.2e6, 2.5e-8, '4.835 978 91(12) e14 Hz/V', 'CODATA 2006'],
'bohrmagn':['Bohr magneton = e hbar/(2 m_e)', 'mu_B', 9.27400915e-24, 2.3e-31, 2.5e-8, '9.274 009 15(23) e-24 J/T', 'CODATA 2006'],
'nuclmagn':['nuclear magneton = e hbar/(2 m_p)', 'mu_N', 5.05078324e-27, 1.3e-34, 2.5e-8, '5.050 783 24(13) e-27 J/T', 'CODATA 2006'],
'magnmom-e':['electron magnetic moment', 'mu_e', -9.28476377e-24, 2.3e-31, 2.5e-8, '-9.284 763 77(23) e-24 J/T', 'CODATA 2006'],
'magnmom-p':['proton magnetic moment', 'mu_p', 1.41060662e-26, 3.7e-33, 2.5e-8, '1.410 606 662(37) e-26 J/T', 'CODATA 2006'],
'gfactor-e':['electron g-factor', 'g_e', -2.0023193043622, 1.5e-12, 7.4e-13, '-2.002 319 304 3622(15)', 'CODATA 2006'],
'gfactor-p':['proton g-factor', 'g_p', 5.585694713, 4.6e-8, 8.2e-9, '5.585 694 713(46)', 'CODATA 2006'],
'alpha':['fine-structure constant = e^2/(4 pi eps_0 hbar c)', 'alpha', 7.2973525376e-3, 5.0e-12, 6.8e-10, '7.297 352 5376(50) e-3', 'CODATA 2006'],
'alpha-1':['inverse fine-structure constant = 4 pi eps_0 hbar c/e^2', '', 137.035999679, 9.4e-8, 6.8e-10, '137.035 999 679(94)', 'CODATA 2006'],
'gyromagratio-p':['proton gyromagnetic ratio', 'gamma_p', 2.675222099e8, 7.0, 2.6e-8, '2.675 222 099(70) e8 s^-1 T^-1', 'CODATA 2006'],
'magres-p':['magnetic resonance frequency proton = gamma_p/(2*pi)', '', 4.25774821e7, 1.1, 2.6e-8, '42.577 4821(11) MHz/T', 'CODATA 2006'],
'rydberg':['Rydberg constant = alpha^2 m_e c/(2 h)', 'R_infty', 10973731.568527, 7.3e-5, 6.6e-12, '10 973 731.568 527(73) m^-1', 'CODATA 2006'],
'stefan-boltzm':['Stefan-Boltzmann constant = pi^2 k^4/(60 hbar^3 c^2)', 'sigma', 5.670400e-8, 4.0e-13, 7.0e-6, '5.670 400(40) e-8 W m^-2 K^-4', 'CODATA 2006']}
# many common values are also available as global constants:
global alpha, a_0, c, e, eps_0, F, G, g_e, g_p, gamma_p, h, hbar, k_B
global m_d, m_e, m_n, m_p, mu_B, mu_e, mu_N, mu_p, mu_0, N_A, R, sigma, u
alpha = all_dict['alpha'][2]
a_0 = all_dict['bohrradius'][2]
c = cloc
e = all_dict['charge-e'][2]
eps_0 = all_dict['elec-const'][2]
F = all_dict['faraday'][2]
G = all_dict['gravit'][2]
g_e = all_dict['gfactor-e'][2]
g_p = all_dict['gfactor-p'][2]
gamma_p = all_dict['gyromagratio-p'][2]
h = all_dict['planck'][2]
hbar = all_dict['dirac'][2]
k_B = all_dict['boltzmann'][2]
m_d = all_dict['mass-d'][2]
m_e = all_dict['mass-e'][2]
m_n = all_dict['mass-n'][2]
m_p = all_dict['mass-n'][2]
mu_B = all_dict['bohrmagn'][2]
mu_e = all_dict['magnmom-e'][2]
mu_N = all_dict['nuclmagn'][2]
mu_p = all_dict['magnmom-p'][2]
mu_0 = all_dict['magn-const'][2]
N_A = all_dict['avogadro'][2]
R = all_dict['gas'][2]
sigma = all_dict['stefan-boltzm'][2]
u = all_dict['amu'][2]
[docs]
def help():
'''
Print help.
See :py:mod:`h5utils.constants.physcon` for examples.
'''
print('Available functions:')
print('[note: key must be a string, within quotes!]')
print(' value(key) returns value (float)')
print(' sd(key) returns standard deviation (float)')
print(' relsd(key) returns relative standard deviation (float)')
print(' descr(key) prints description with units\n')
print('Available global variables:')
print(' alpha, a_0, c, e, eps_0, F, G, g_e, g_p, gamma_p, h, hbar, k_B')
print(' m_d, m_e, m_n, m_p, mu_B, mu_e, mu_N, mu_p, mu_0, N_A, R, sigma, u\n')
allkeys = list(all_dict.keys())
allkeys.sort()
print('Available keys:')
print(allkeys)
[docs]
def value(key):
'''
Print value.
See :py:mod:`h5utils.constants.physcon` for examples.
'''
return all_dict[key][2]
[docs]
def sd(key):
'''
Print standard deviation.
See :py:mod:`h5utils.constants.physcon` for examples.
'''
return all_dict[key][3]
[docs]
def relsd(key):
'''
Print relative standard deviation.
See :py:mod:`h5utils.constants.physcon` for examples.
'''
return all_dict[key][4]
[docs]
def descr(key):
'''
Print description.
See :py:mod:`h5utils.constants.physcon` for examples.
'''
print('Description of ', key, ':')
print(' Name: ', all_dict[key][0])
print(' Symbol (if avail.): ', all_dict[key][1])
print(' Value: ', all_dict[key][2])
print(' Standard deviation: ', all_dict[key][3])
print(' Relative stdev: ', all_dict[key][4])
print(' value(sd) unit: ', all_dict[key][5])
print(' Source: ', all_dict[key][6], '\n')
# Accessors based on naming system originally used in Matlab scripts (and Maple?)
[docs]
def get_c0():
'''
Returns the speed of light in SI units (m/s).
See :py:mod:`h5utils.constants.physcon` for examples.
'''
return value('lightvel')
[docs]
def get_e():
'''
Returns the charge of an electron in SI units (Coulomb).
See :py:mod:`h5utils.constants.physcon` for examples.
'''
return value('charge-e')
[docs]
def get_eV():
'''
Returns 1eV in SI units (Joules).
See :py:mod:`h5utils.constants.physcon` for examples.
'''
return get_e()
[docs]
def get_epsilon0():
'''
Returns the dielectric permittivity of vacuum in SI units (F/m).
See :py:mod:`h5utils.constants.physcon` for examples.
'''
return value('elec-const')
[docs]
def get_mu0():
'''
Returns the magnetic permeability of vacuum in SI units (N*A^-2).
See :py:mod:`h5utils.constants.physcon` for examples.
'''
return value('magn-const')
[docs]
def get_h():
'''
Returns Planck's constant in SI units (J*s).
See :py:mod:`h5utils.constants.physcon` for examples.
'''
return value('planck')
[docs]
def get_h_eVs():
'''
Returns Planck's constant in eV.
See :py:mod:`h5utils.constants.physcon` for examples.
'''
return get_h()/get_e()
[docs]
def get_hb():
'''
Returns Dirac's constant = h/(2 pi) in SI units (J*s).
See :py:mod:`h5utils.constants.physcon` for examples.
'''
return value('dirac')
[docs]
def get_me():
'''
Returns the electron mass in SI units (kg).
See :py:mod:`h5utils.constants.physcon` for examples.
'''
return value('mass-e')
if __name__ == '__main__':
pass