Iron: properties of free atoms
Iron atoms have 26 electrons and the shell structure is 18.104.22.168.
The ground state electron configuration of ground state gaseous neutral iron is [Ar].3d6.4s2 and the term symbol is 5D4.
A representation of the atomic spectrum of iron.
Ionisation Energies and electron affinity
The electron affinity of iron is 15.7 kJ mol‑1. The ionisation energies of iron are given below.
Effective Nuclear Charges
The following are "Clementi-Raimondi" effective nuclear charges, Zeff. Follow the hyperlinks for more details and for graphs in various formats.
|4s||5.43||4p||(no data)||4d||(no data)||4f||(no data)|
|5s||(no data)||5p||(no data)||5d||(no data)|
|6s||(no data)||6p||(no data)|
These effective nuclear charges, Zeff, are adapted from the following references:
- E. Clementi and D.L.Raimondi, J. Chem. Phys. 1963, 38, 2686.
- E. Clementi, D.L.Raimondi, and W.P. Reinhardt, J. Chem. Phys. 1967, 47, 1300.
Electron binding energies
|Label||Orbital||eV [literature reference]|
|L I||2s||844.6 |
|L II||2p1/2||719.9 |
|L III||2p3/2||706.8 |
|M I||3s||91.3 |
|M II||3p1/2||52.7 |
|M III||3p3/2||52.7 |
I am grateful to Gwyn Williams (Jefferson Laboratory, Virginia, USA) who provided the electron binding energy data. The data are adapted from references 1-3. They are tabulated elsewhere on the WWW (reference 4) and in paper form (reference 5).
- J. A. Bearden and A. F. Burr, "Reevaluation of X-Ray Atomic Energy Levels," Rev. Mod. Phys., 1967, 39, 125.
- M. Cardona and L. Ley, Eds., Photoemission in Solids I: General Principles (Springer-Verlag, Berlin) with additional corrections, 1978.
- Gwyn Williams WWW table of values
- D.R. Lide, (Ed.) in Chemical Rubber Company handbook of chemistry and physics, CRC Press, Boca Raton, Florida, USA, 81st edition, 2000.
- J. C. Fuggle and N. Mårtensson, "Core-Level Binding Energies in Metals," J. Electron Spectrosc. Relat. Phenom., 1980, 21, 275.