Acronym quittin Name quasitruncated penteract Field of sections ` ©` Circumradius sqrt[13-8 sqrt(2)]/2 = 0.649286 Inradiuswrt. quitit [sqrt(2)-1]/2 = 0.207107 Inradiuswrt. pen (5-4 sqrt(2))/sqrt(20) = -0.146877 Vertex figure ` ©` Coordinates ((sqrt(2)-1)/2, (sqrt(2)-1)/2, (sqrt(2)-1)/2, (sqrt(2)-1)/2, 1/2)   & all permutations, all changes of sign Volume (1230-869 sqrt(2))/30 = 0.034947 Confer analogs: quasitruncated hypercube qtCn Externallinks

As abstract polytope tan is isomorphic to quittin, thereby replacing octagons by octagrams, resp. tic by quith, resp. tat by quitit.

Note that the tets and pens become retrograde here.

Incidence matrix according to Dynkin symbol

```o3o3o3x4/3x

. . . .   . | 160 |   4  1 |   6  4 |   4  6 |  1  4
------------+-----+--------+--------+--------+------
. . . x   . |   2 | 320  * |   3  1 |   3  3 |  1  3
. . . .   x |   2 |   * 80 ♦   0  4 |   0  6 |  0  4
------------+-----+--------+--------+--------+------
. . o3x   . |   3 |   3  0 | 320  * |   2  1 |  1  2
. . . x4/3x |   8 |   4  4 |   * 80 |   0  3 |  0  3
------------+-----+--------+--------+--------+------
. o3o3x   . ♦   4 |   6  0 |   4  0 | 160  * |  1  1
. . o3x4/3x ♦  24 |  24 12 |   8  6 |   * 40 |  0  2
------------+-----+--------+--------+--------+------
o3o3o3x   . ♦   5 |  10  0 |  10  0 |   5  0 | 32  *
. o3o3x4/3x ♦  64 |  96 32 |  64 24 |  16  8 |  * 10
```