template Mixture(20)
  char name           ! mixture name
  int nmat            ! number of materials
  material matnames(5)    ! material names
  real prop(5)        ! prop by volume
end template

!               name        nmat     material names                       prop by volume

make Mixture "ARGON-ETHAN"   2  "ARGON"  "C2H6"  "-" "-" "-"       0.65  0.35  0.00  0.00  0.00