Temperature

The temperature T is directly related to the kinetic energy by the well-known equipartition formula, assigning an average kinetic energy k_B T / 2 per degree of freedom:  

$$K = \frac{3}{2} N k_B T$$ (10)

An estimate of the temperature is therefore directly obtained from the average kinetic energy K (see §3.5.2). For practical purposes, it is also common practice to define an ``instantaneous temperature'' T(t), proportional to the instantaneous kinetic energy K(t) by a relation analogous to the one above.