Figure 2: Demonstration of the smooth extrapolation property of the proposed approach.

Example of one-dimensional potential (red curves) (
) varying with the value of some external variable α (such as composition). (a) The energy (at 0 K) is given by the local minimum (blue) if it exists, and by the inflection point (green) when instability occurs. (b) The energy thus defined is a smooth function of α, even at the onset of instability (marked by a vertical dash).