Hartree
The Hartree Eh, also known as the Hartree energy, is a physical constant, which is used in the Hartree atomic units system and named after the British physicist Douglas Hartree. It is defined as
2R∞hc, where R∞ is the Rydberg constant, h is the Planck constant and c is the speed of light. Its CODATA recommended value is =
The Hartree energy is approximately the electric potential energy of the hydrogen atom in its ground state and, by the virial theorem, approximately twice its ionization energy; the relationships are not exact because of the finite mass of the nucleus of the hydrogen atom and relativistic corrections.
The Hartree is usually used like a unit of energy in atomic physics and computational chemistry: for experimental measurements at the atomic scale, the electronvolt or the reciprocal centimetre are much more widely used.Other relationships
where:
Note that since the Bohr radius is defined as
one may write the Hartree energy as in Gaussian units where. Effective Hartree units are used in semiconductor physics where is replaced by and is the static dielectric constant. Also, the electron mass is replaced by the effective band mass. The effective Hartree in semiconductors becomes small enough to be measured in millielectronvolts.
