A (so far small) set of (mostly physics related) constants defined in the units of Unchained.
c = 299792458.0
e = 1.602176634e-19
G_Newton = 6.6743e-11
hp = 6.62607015e-34
hp_bar = 1.0545718176461565e-34
k_B = 1.380649e-23
m_e = 9.1093837015e-31
m_e_c2 = 0.510998928
m_u = 1.660539066592658e-27
M_u = 0.00099999999965
m_μ = 1.883531627e-28
m_μ_eV = 105658375.5
N_A = 6.02214076e+23
r_e = 2.817940326204928e-15
ε_0 = 8.8541878128e-12
Ï€ = 3.141592653589793