constants.hpp

// constants.hpp
#pragma once
 
namespace constants {
    constexpr double pi   = 3.14159265358979323846;
    constexpr double e    = 2.71828182845904523536;
    constexpr double q_e  = 1.602176634e-19;        // electron charge (C)
    constexpr double m_e  = 9.109e-31;              // electron mass (kg)
    constexpr double c    = 2.99792458e8;           // speed of light (m/s)
    constexpr double eps0 = 8.854187817e-12;        // As/Vm
    constexpr double hbar = 1.054571817e-34;        // J·s
    constexpr double kB   = 1.380649e-23;           // J/K
    constexpr double A    = 1.20173e6;              // Richardson const A/(m·K)^2
    constexpr double G    = 6.67430e-11;            // m^3/(kg·s^2)
}