Hartree

The Hartree is a unit of energy commonly used in atomic and molecular physics, particularly in quantum chemistry. It is defined as approximately \(4.36 \times 10^{-18}\) joules or \(27.2\) electron volts (eV). The Hartree energy is equivalent to the energy of an electron in the electrostatic field of a proton, and thus it provides a convenient scale for measuring energy levels and interactions in atoms and molecules.