Elementary charge.
value = echarge [value,sigma] = echarge
echarge returns the value of the elementary electric charge
in SI units (Coulomb) in value and the standard
deviation in sigma (if two output arguments are specified).
The value and the standard deviation are taken from the 2002 CODATA collection of recommended values.
amu, avogadro, barn, bmagn, bohrrad, boltzm, clight, emass, faraday, gfree, hartree, molgas, nmagn, nmass, planck, pmass, rydberg