X-ray Notation
Get X-ray Notation essential facts below. View Videos or join the X-ray Notation discussion. Add X-ray Notation to your PopFlock.com topic list for future reference or share this resource on social media.
X-ray Notation

X-ray notation is a method of labeling atomic orbitals that grew out of X-ray science. Also known as IUPAC notation, it was adopted by the International Union of Pure and Applied Chemistry in 1991 as a simplification of the older Siegbahn notation.[1] In X-ray notation, every principal quantum number is given a letter associated with it. In many areas of physics and chemistry, atomic orbitals are described with spectroscopic notation (1s, 2s, 2p, 3s, 3p, etc.), but the more traditional X-ray notation is still used with most X-ray spectroscopy techniques including AES and XPS.

## Conversion

Conversion[2][3]
Quantum numbers Atomic notation X-ray notation
${\displaystyle n}$ ${\displaystyle \ell }$ ${\displaystyle s}$ ${\displaystyle j}$
1 0 ±1/2 1/2 1S1/2 K1
2 0 ±1/2 1/2 2S1/2 L1
2 1 -1/2 1/2 2P1/2 L2
2 1 +1/2 3/2 2P3/2 L3
3 0 ±1/2 1/2 3S1/2 M1
3 1 -1/2 1/2 3P1/2 M2
3 1 +1/2 3/2 3P3/2 M3
3 2 -1/2 3/2 3D3/2 M4
3 2 +1/2 5/2 3D5/2 M5

## Uses

• X-ray sources are classified by the type of material and orbital used to generate them. For example, CuK? X-rays are emitted from the K orbital of copper.
• X-ray absorption is reported as which orbital absorbed the x-ray photon. In EXAFS and XMCD the L-edge or the L absorption edge is the point where the L orbital begins to absorb x-rays.
• Auger peaks are identified with three orbital definitions, for example KL1L2. In this case, K represents the hole that is initially present at the core level, L1 the initial state of the electron that relaxes down into the core level hole, and L2 the initial energy state of the emitted electron.

## References

1. ^ R. JENKINS, R. MANNE, R. ROBIN and C. SENEMAUD (1991). "NOMENCLATURE SYSTEM FOR X-RAY SPECTROSCOPY" (pdf). IUPAC. Retrieved 2018.CS1 maint: multiple names: authors list (link)
2. ^ Dr. Garrett's Class Notes page 12 http://www.cem.msu.edu/~cem924sg/Topic09.pdf Retrieved 10-07-08
3. ^ IUPAC Table VIII.1 page 5 http://old.iupac.org/reports/V/spectro/partVIII.pdf Retrieved 30-05-09