### degeneracy weight

**(statistical weight, degeneracy, degeneracy weighting)**
(number of quantum states with same energy level)

**Degeneracy weight** (or **statistical weight**, **degeneracy weighting**,
or simply degeneracy) is a count of the **quantum states**
of an atom (state of excitation) that have the same energy level.
It is useful when the number of particles at a particular energy level
is what's directly needed rather than their exact quantum states.

It is used in the Boltzmann equation. The energy levels considered
"the same" might be extremely close, but not exact,
a difference that leads to forbidden lines, fine structure
and hyperfine structure.

(*physics,quantum mechanics*)
http://en.wikipedia.org/wiki/Statistical_weight

http://en.wikipedia.org/wiki/Maxwell-Boltzmann_statistics

**Referenced by:**

Boltzmann equation

index