[1] Its Coxeter symbol is 321, describing its bifurcating Coxeter-Dynkin diagram, with a single ring on the end of one of the 3-node sequences.
The 56 vertices can be most simply represented in 8-dimensional space, obtained by the 28 permutations of the coordinates and their opposite: Its construction is based on the E7 group.
Coxeter named it as 321 by its bifurcating Coxeter-Dynkin diagram, with a single ring on the end of the 3-node sequence.
Seen in a configuration matrix, the element counts can be derived by mirror removal and ratios of Coxeter group orders.
Thorold Gosset identified this series in 1900 as containing all regular polytope facets, containing all simplexes and orthoplexes.
Coxeter named it as 321 by its bifurcating Coxeter-Dynkin diagram, with a single node on the end of the 3-node sequence.
Removing the node on the end of the 2-length branch leaves the rectified 6-orthoplex in its alternated form: t1311, .
Coxeter named it as 321 by its bifurcating Coxeter-Dynkin diagram, with a single node on the end of the 3-node sequence.
Removing the node on the end of the 3-length branch leaves the rectified 221 polytope in its alternated form: t1(221), .