Hartree energy

The Hartree energy (symbol E_h) is a physical constant used as atomic unit of energy, named after physicist Douglas Hartree[?].

It has a value of twice the binding energy of the electron in the ground state of the hydrogen atom.

<math>E_h = {\hbar^2 \over {m_e a^2_0}}</math>

= 4.359 743 81(34) x 10^-18J

where:

<math>\hbar</math> is the Dirac's constant,

<math>m_e</math> is the electron rest mass

<math>a_0</math> is the Bohr radius