The "stack of fourths" chord where the fourths are tempered narrow so that the outer interval approaches 3:7, and the bass-alto and tenor-soprano intervals approach 4:7. To the 2 cent accuracy of the calculation, this is the same as the 22-tET tuning of the "stack of fourths." This clearly shows that the relationship between concordance and JI is quite different when dealing with dyads vs. dealing with larger chords, even when the model only takes dyadic discordance, with local minima at JI ratios, into account. Also, since the triadic analogue to this calculation showed a local minimum at 0__498__996 cents, this model agrees with George Kahrimanis that while a stack of two fourths sounds best pure, a stack of three fourths can be improved with some temperament.
