Boltzmann average
From SklogWiki
The Boltzmann average (sometimes known as the thermal average) for a given quantity or observable, let us say \(A\), is given by
\[\langle A \rangle = \frac{\sum_i A_i \exp(-E_i/k_B T)}{\sum_i\exp(-E_i/k_B T)}\]
where \(k_B\) is the Boltzmann constant, and T is the temperature. This provides the expected value of the property in question at a given temperature.
