  We show that the extended cosmological equation-of-state developed starting
from a Chaplygin equation-of-state, recently applied to stellar modeling, is a
viable dark energy model consistent with standard scalar potentials. Moreover
we find a Lagrangian formulation based on a canonical scalar field with the
appropriate self-interaction potential. Finally, we fit the scalar potential
obtained numerically with concrete functions well studied in the literature.
Our results may be of interest to model builders and particle physicists.
