which has a maximum of 0.7k B at x = 1 2 . Related contributions will play a role in materials with other degrees of freedom such partial occupancy of crystallographic positions (e.g. non-stoichiometric Fe 1 -x O) or magnetic ordering (e.g. for magnetocaloric materials). Configurational entropy can also be extended to multiple species, most strikingly in the case of high entropy alloys. In many cases, the assumption of randomly distributed species is too simple because of short-range order. Local ordering results in a decrease in enthalpy at the cost of a lower entropy. The cluster expansion method coupled with Monte Carlo simulations and the symmetryadapted enumeratuion method have been successful in modelling these effects.