Atomic unit of energy.

value = hartree
[value,sigma] = hartree

hartree returns the value of 1 Hartree (atomic unit of energy) in SI units (joule) in value and the standard deviation in sigma (if two output arguments are specified).

The value and the standard deviation are taken from the 2018 CODATA collection of recommended values.

amu, angstrom, avogadro, barn, bmagn, bohrrad, boltzm, clight, echarge, emass, eps0, evolt, faraday, gammae, gfree, hbar, molgas, mu0, nmagn, nmass, planck, pmass, rydberg