Acronym	enne
Name	enneract, octadecayotton, 9D measure-polytope (γ9), geoxenn(id)
Circumradius	3/2 = 1.5
Inradius	1/2
Vertex layers	Layer Symmetry Subsymmetries   o3o3o3o3o3o3o3o4o o3o3o3o3o3o3o3o . . o3o3o3o3o3o3o4o 1 o3o3o3o3o3o3o3o4x o3o3o3o3o3o3o3o . vertex first . o3o3o3o3o3o3o4x octo first 2 o3o3o3o3o3o3o3q . vertex figure . o3o3o3o3o3o3o4x opposite octo 3 o3o3o3o3o3o3q3o .   4 o3o3o3o3o3q3o3o . 5 o3o3o3o3q3o3o3o . 6 o3o3o3q3o3o3o3o . 7 o3o3q3o3o3o3o3o . 8 o3q3o3o3o3o3o3o . 9 q3o3o3o3o3o3o3o . 10 o3o3o3o3o3o3o3o . opposite vertex
Coordinates	(1/2, 1/2, 1/2, 1/2, 1/2, 1/2, 1/2, 1/2, 1/2)   & all changes of sign
Volume	1
Surface	18
Dual	vee
Dihedral angles (at margins)	at hept between octo and octo:   90°
Face vector	512, 2304, 4608, 5376, 4032, 2016, 672, 144, 18
Confer	general polytopal classes: Wythoffian polyyotta   hypercube   noble polytopes   segmentoyotta   analogs: regular hypercube Cn
External links

Its equatorial cross-section in vertex first orientation is not a vertex layer. Even so it can be determined as 1/q-be (cf. truncation series).

Incidence matrix according to Dynkin symbol

o3o3o3o3o3o3o3o4x

. . . . . . . . . | 512 ♦    9 |   36 |   84 |  126 |  126 |  84 |  36 |  9
------------------+-----+------+------+------+------+------+-----+-----+---
. . . . . . . . x |   2 | 2304 ♦    8 |   28 |   56 |   70 |  56 |  28 |  8
------------------+-----+------+------+------+------+------+-----+-----+---
. . . . . . . o4x |   4 |    4 | 4608 ♦    7 |   21 |   35 |  35 |  21 |  7
------------------+-----+------+------+------+------+------+-----+-----+---
. . . . . . o3o4x ♦   8 |   12 |    6 | 5376 ♦    6 |   15 |  20 |  15 |  6
------------------+-----+------+------+------+------+------+-----+-----+---
. . . . . o3o3o4x ♦  16 |   32 |   24 |    8 | 4032 ♦    5 |  10 |  10 |  5
------------------+-----+------+------+------+------+------+-----+-----+---
. . . . o3o3o3o4x ♦  32 |   80 |   80 |   40 |   10 | 2016 ♦   4 |   6 |  4
------------------+-----+------+------+------+------+------+-----+-----+---
. . . o3o3o3o3o4x ♦  64 |  192 |  240 |  160 |   60 |   12 | 672 |   3 |  3
------------------+-----+------+------+------+------+------+-----+-----+---
. . o3o3o3o3o3o4x ♦ 128 |  448 |  672 |  560 |  280 |   84 |  14 | 144 |  2
------------------+-----+------+------+------+------+------+-----+-----+---
. o3o3o3o3o3o3o4x ♦ 256 | 1024 | 1792 | 1792 | 1120 |  448 | 112 |  16 | 18

snubbed forms: o3o3o3o3o3o3o3o4s