The
q-state Potts model on the triangular lattice with both two- and three-spin interactions
K and
L (the Schick-Griffiths model) is shown to be equivalent to the
q-state Potts model on a 3-12 lattice with only two-spin interactions
J1 and
J2. In particular, the
J1>0 and
J2>0 model is mapped into a Schick-Griffiths model for a range of the coupling parameters
K and
L, so that the two models are in the same universality class. We also show that a recent conjecture by Tsallis on the critical point of the 3-12 model is incorrect.