c ----------- speed of light .......... 2.9979e8 m/s ....... 2.9979e10 cm/s
e ----------- electron charge ......... 1.6022e-19 C ....... 4.8032e-10 esu
h-bar ------- Planck's constant ....... 1.0546e-34 J s ..... 1.0546e_27 erg s
N ----------- Avogadro's Number .................. 6.0222e23 1/mol
amu --------- atomic mass unit ........ 1.6605e-27 kg ...... 1.6605e-24 gm
m ----------- electron rest mass ...... 9.1096e-31 kg ...... 9.1096e-28 g
eV ---------- electron volt ........... 1.6022e-19 J ....... 1.6022e-12 erg
eh-bar/2mc -- Bohr magneton ........... 9.2741e-24 J/T ..... 9.2741e-21 erg/G
k_B --------- Boltzmann constant ...... 1.3806e-23 J/K ..... 1.3806e-16 erg/K
epsilon_0 --- permittivity of space ... 8.8541e-12 F/m ..... 1
mu_0 -------- permeability of space ... 4*pi*e-7 H/m ....... 1
e^2/h-bar*c - fine structure constant ............. 1/137.036