home/UsefulConstants.md

@@ -3,3 +3,5 @@ In units where the reduced Planck constant $\hbar = 1$, the Boltzmann constant i
 - The electron charge squared is $e^2 = 14.399$ $Å\text{eV}$
 - The elementary electron mass is $m_e = 0.1314$ $Å^{-2} \text{eV}^{-1}$
 - The temperature (in Kelvin) is given by $T[K] = T[\text{eV}] / k_B[\text{eV}]$, where $k_B[\text{eV}] = 8.617333262 \times 10^{-5}$ eV/K
+- The speed of light is $c = e^2/\alpha = 1973.181$ $Å\text{eV}$, where $\alpha$ is the fine-structure constant
+- The vacuum permeability is $\mu_0 = 4 \pi / c^2 = 3.228 \times 10^{-6}$ $Å^{-2}\text{eV}^{-2}$
\ No newline at end of file