  I present an overview of an equation of state, being developed in the
chemical picture, and based on the very successful MHD equation of state. The
flexibility of the chemical picture combined with the free-energy minimization
procedure, makes it rather straight-forward, albeit laborious, to include new
effects in the model free-energy, simply by adding new terms.
  The most notable additions to the original MHD equation of state, are
relativistic effects, quantum effects, improved higher order Coulomb terms and
a long list of molecules other than the H2 and H2+ treated so far.
