| 1 hartree = |
|---|
| 4.359 743 94(22) × 10−18 J | | 27.211 383 86(68) eV |
|
Energy equivalents| 1 hartree ≜ |
|---|
| Molar energy |
|---|
| 2612.563 2271(27) kJ mol−1 | | 624.417 597 29(66) kcal mol−1 | | Mass |
|---|
| 4.850 869 34(24) × 10−35 kg | | 2.921 262 2986(42) × 10−8 u | | Frequency/wavenumber |
|---|
| 6.579 683 920 722(44) × 109 MHz | | 219 474.631 3705(15) cm−1 | | Temperature |
|---|
| 315 774.65(55) K |
|
The hartree (symbol: Eh), also known as the Hartree energy, is the atomic unit of energy,[1] named after the British physicist Douglas Hartree. It is defined as the electric potential energy of the hydrogen atom in its ground state, and is equal to 2R∞hc0, where R∞ is the Rydberg constant, h is the Planck constant and c0 is the speed of light. The 2006 CODATA recommended value is Eh = 4.359 743 94(22) × 10−18 J = 27.211 383 86(68) eV.[2]
The hartree energy is approximately twice the ionization energy of hydrogen: the relationship is not exact because the nucleus of the hydrogen atom does not have infinite mass. However, the relationship Eh = 2R∞hc0 is exact, as the effects of non-infinite nuclear mass are already considered in the Rydberg constant (hence the subscript infinity).
The hartree is usually used as a unit of energy in calculational chemistry: for experimental measurements at the atomic scale, the electronvolt (eV) or the reciprocal centimetre (cm−1) are much more widely used.
References
- ↑ hartree, <http://goldbook.iupac.org/H02747.html> (accessed 28 March 2010), Compendium of Chemical Terminology Internet edition; International Union of Pure and Applied Chemistry (IUPAC). Hartree energy, <http://goldbook.iupac.org/H02748.html> (accessed 28 March 2010), Compendium of Chemical Terminology Internet edition; International Union of Pure and Applied Chemistry (IUPAC).
- ↑ Mohr, Peter J.; Taylor, Barry N.; Newell, David B. CODATA Recommended Values of the Fundamental Physical Constants: 2006. Rev. Mod. Phys. 2008, 80 (2), 633–730. doi:10.1103/RevModPhys.80.633, <http://physics.nist.gov/cuu/Constants/codata.pdf>. Direct link to value.
External links
