subsection Material model
  set Model name = composition reaction

  subsection Composition reaction model
    set Thermal conductivity                           = 1e-6
    set Thermal expansion coefficient                  = 0.01
    set Viscosity                                      = 1
    set Density differential for compositional field 1 = -5
    set Density differential for compositional field 2 = 5
    set Reaction depth                                 = 0.2
  end
end
