-- physical constants (c, e, h, and k are exact values) c = 299792458.0 meter / second -- speed of light in vacuum e = 1.602176634 10^(-19) coulomb -- elementary charge epsilon0 = 8.8541878128 10^(-12) farad / meter -- vacuum electric permittivity h = 6.62607015 10^(-34) joule second -- Planck constant hbar = h / float(2 pi) -- reduced Planck constant k = 1.380649 10^(-23) joule / kelvin -- Boltzmann constant me = 9.1093837015 10^(-31) kilogram -- electron mass mp = 1.67262192369 10^(-27) kilogram -- proton mass mu = me mp / (me + mp) -- reduced electron mass -- derived units coulomb = ampere second farad = coulomb / volt joule = kilogram meter^2 / second^2 volt = joule / coulomb -- base units (for printing) ampere = "ampere" kelvin = "kelvin" kilogram = "kilogram" meter = "meter" second = "second" electronvolt = e joule / coulomb -- convert electronvolt to joule Run