The tutonic sextad is an essentially tempered chord of the tutone temperament, which is every other member of the generator chain of 11-limit meantone (Huygens). This means it is 9/8-9/8-9/8-9/8-9/8-8/7 tempered by {81/80, 99/98, 126/125}, or in other words the tempering of 9/8-5/4-7/5-11/7-7/4-2.