''' Planck constant [J s] ''' .h = 6.62607015e-34 ''' Dirac constant (ħ = h/2π) [J s] ''' .ħ = 1.054571817e-34 ''' Velocity of light [m s^-1] ''' .c = 2.99792458e+8 ''' Electric constant [F m^-1] ''' .ε_0 = 8.8541878128e-12 ''' Magnetic constrant [N A^-2] ''' .μ_0 = 1.25663706212e-6 ''' Standard gravity [m s^-2] ''' .g = 9.80665 ''' Gravitational constant [m^3 kg^-1 s^-2] ''' .G = 6.67430e-11 ''' Fine structure constant [dimensionless] ''' .α = 7.2973525693e-3 ''' Bolzmann constant [J K^-1] ''' .k_B = 1.380649e-23 ''' Avogadro constant [mol^-1] ''' .N_A = 6.02214076e+23 ''' Rydberg constant [m^-1] ''' .R_inf = 10973731.568160