Although a linear model function will seldom be the best choice, there are at least two situations in which it could be: (1) when only two data points are available, presumably from an extremely costly method, and (2) when more than two data points are available but they contain noise that must be mitigated by an averaging process such as least-squares fitting. Situation #2 is especially relevant for stochastic methods of electronic structure. Note that the energy minimum, Ee, and its location, Re, can also be determined from only two points by using eq. ( ).