Various physical constants now available. The values are extracted from:

Symbol Description Value Unit
\(\mu\) Atomic mass constant \(1.660539040\,.10^{-27}\) \(kg\)
\(N_{a}\) Avogadro constant \(6.022140857\,.10^{23}\) \(\mathrm{mol}^{-1}\)
\(k_{b}\) Boltzmann constant \(1.38064852\,.10^{-23}\) \(J.K^{-1}\)
\(G_{0}\) Conductance quantum \(7.7480917310\,.10^{-5}\) \(S\)
\(e_{0}\) Electric constant \(8.854187817\,.10^{-12}\) \(F.m^{-1}\)
\(m_{e}\) Electron mass \(9.10938356\,.10^{-31}\) \(kg\)
\(eV\) Electron volt \(1.6021766208\,.10^{-19}\) \(J\)
\(e\) Elementary charge \(1.6021766208\,.10^{-19}\) \(C\)
\(F\) Faraday constant \(96485.33289\) \(C.\mathrm{mol}^{-1}\)
\(a\) Fine-structure constant \(7.2973525664\,.10^{-3}\)
\(R\) Molar gas constant \(8.3144598\) \(J.\mathrm{mol}^{-1}.K^{-1}\)
\(s\) Stefan-Boltzmann constant \(5.670367\,.10^{-8}\) \(W.m^{-2}.K^{-4}\)


The physical constants are available as constexpr static members of tfel::PhysicalConstants class defined in the TFEL/PhysicalConstants.hxx header.

using Cste   = tfel::PhysicalConstants<real>;
const auto R = Cste::R;


The physical constants are available as members of the tfel.PhysicalConstants class, as follows:

from tfel import PhysicalConstants as Cste