Acronym stopen Name octagram-pentachoron duoprism Circumradius sqrt[(19-5 sqrt(2))/10] = 1.092197 Confer more general: n,pen-dip

As abstract polytope stopen is isomoph to open, then replacing octagrams by octagons, resp. stop by op, resp. tistodip by todip, resp. stotet by otet.

Incidence matrix according to Dynkin symbol

```x8/3o x3o3o3o

.   . . . . . | 40 |  2  4 | 1  8  6 |  4 12  4 |  6  8 1 | 4 2
--------------+----+-------+---------+----------+---------+----
x   . . . . . |  2 | 40  * | 1  4  0 |  4  6  0 |  6  4 0 | 4 1
.   . x . . . |  2 |  * 80 | 0  2  3 |  1  6  3 |  3  6 1 | 3 2
--------------+----+-------+---------+----------+---------+----
x8/3o . . . . |  8 |  8  0 | 5  *  * ♦  4  0  0 |  6  0 0 | 4 0
x   . x . . . |  4 |  2  2 | * 80  * |  1  3  0 |  3  3 0 | 3 1
.   . x3o . . |  3 |  0  3 | *  * 80 |  0  2  2 |  1  4 1 | 2 2
--------------+----+-------+---------+----------+---------+----
x8/3o x . . . ♦ 16 | 16  8 | 2  8  0 | 10  *  * |  3  0 0 | 3 0
x   . x3o . . ♦  6 |  3  6 | 0  3  2 |  * 80  * |  1  2 0 | 2 1
.   . x3o3o . ♦  4 |  0  6 | 0  0  4 |  *  * 40 |  0  2 1 | 1 2
--------------+----+-------+---------+----------+---------+----
x8/3o x3o . . ♦ 24 | 24 24 | 3 24  8 |  3  8  0 | 10  * * | 2 0
x   . x3o3o . ♦  8 |  4 12 | 0  6  8 |  0  4  2 |  * 40 * | 1 1
.   . x3o3o3o ♦  5 |  0 10 | 0  0 10 |  0  0  5 |  *  * 8 | 0 2
--------------+----+-------+---------+----------+---------+----
x8/3o x3o3o . ♦ 32 | 32 48 | 4 48 32 |  6 32  8 |  4  8 0 | 5 *
x   . x3o3o3o ♦ 10 |  5 20 | 0 10 20 |  0 10 10 |  0  5 2 | * 8
```

```x4/3x x3o3o3o

.   . . . . . | 40 |  1  1  4 | 1  4  4  6 |  4  6  6  4 |  6  4  4 1 | 4 1 1
--------------+----+----------+------------+-------------+------------+------
x   . . . . . |  2 | 20  *  * | 1  4  0  0 |  4  6  0  0 |  6  4  0 0 | 4 1 0
.   x . . . . |  2 |  * 20  * | 1  0  4  0 |  4  0  6  0 |  6  0  4 0 | 4 0 1
.   . x . . . |  2 |  *  * 80 | 0  1  1  3 |  1  3  3  3 |  3  3  3 1 | 3 1 1
--------------+----+----------+------------+-------------+------------+------
x4/3x . . . . |  8 |  4  4  0 | 5  *  *  * ♦  4  0  0  0 |  6  0  0 0 | 4 0 0
x   . x . . . |  4 |  2  0  2 | * 40  *  * |  1  3  0  0 |  3  3  0 0 | 3 1 0
.   x x . . . |  4 |  0  2  2 | *  * 40  * |  1  0  3  0 |  3  0  3 0 | 3 0 1
.   . x3o . . |  3 |  0  0  3 | *  *  * 80 |  0  1  1  2 |  1  2  2 1 | 2 1 1
--------------+----+----------+------------+-------------+------------+------
x4/3x x . . . ♦ 16 |  8  8  8 | 2  4  4  0 | 10  *  *  * |  3  0  0 0 | 3 0 0
x   . x3o . . ♦  6 |  3  0  6 | 0  3  0  2 |  * 40  *  * |  1  2  0 0 | 2 1 0
.   x x3o . . ♦  6 |  0  3  6 | 0  0  3  2 |  *  * 40  * |  1  0  2 0 | 2 0 1
.   . x3o3o . ♦  4 |  0  0  6 | 0  0  0  4 |  *  *  * 40 |  0  1  1 1 | 1 1 1
--------------+----+----------+------------+-------------+------------+------
x4/3x x3o . . ♦ 24 | 12 12 24 | 3 12 12  8 |  3  4  4  0 | 10  *  * * | 2 0 0
x   . x3o3o . ♦  8 |  4  0 12 | 0  6  0  8 |  0  4  0  2 |  * 20  * * | 1 1 0
.   x x3o3o . ♦  8 |  0  4 12 | 0  0  6  8 |  0  0  4  2 |  *  * 20 * | 1 0 1
.   . x3o3o3o ♦  5 |  0  0 10 | 0  0  0 10 |  0  0  0  5 |  *  *  * 8 | 0 1 1
--------------+----+----------+------------+-------------+------------+------
x4/3x x3o3o . ♦ 32 | 16 16 48 | 4 24 24 32 |  6 16 16  8 |  4  4  4 0 | 5 * *
x   . x3o3o3o ♦ 10 |  5  0 20 | 0 10  0 20 |  0 10  0 10 |  0  5  0 2 | * 4 *
.   x x3o3o3o ♦ 10 |  0  5 20 | 0  0 10 20 |  0  0 10 10 |  0  0  5 2 | * * 4
```

```xx8/3oo ox3oo3oo&#x   → height = sqrt(5/8) = 0.790569
({8/3} || stotet)

o.8/3o. o.3o.3o.    | 8  * | 2  4  0  0 | 1  8  6 0  0  0 | 4 12  4 0  0 0 | 6  8 1 0 0 | 4 2 0
.o8/3.o .o3.o3.o    | * 32 | 0  1  2  3 | 0  2  3 1  6  3 | 1  6  3 3  6 1 | 3  6 1 3 2 | 3 2 1
--------------------+------+------------+-----------------+----------------+------------+------
x.   .. .. .. ..    | 2  0 | 8  *  *  * | 1  4  0 0  0  0 | 4  6  0 0  0 0 | 6  4 0 0 0 | 4 1 0
oo8/3oo oo3oo3oo&#x | 1  1 | * 32  *  * | 0  2  3 0  0  0 | 1  6  3 0  0 0 | 3  6 1 0 0 | 3 2 0
.x   .. .. .. ..    | 0  2 | *  * 32  * | 0  1  0 1  3  0 | 1  3  0 3  3 0 | 3  3 0 3 1 | 3 1 1
..   .. .x .. ..    | 0  2 | *  *  * 48 | 0  0  1 0  2  2 | 0  2  2 1  4 1 | 1  4 1 2 2 | 2 2 1
--------------------+------+------------+-----------------+----------------+------------+------
x.8/3o. .. .. ..    | 8  0 | 8  0  0  0 | 1  *  * *  *  * ♦ 4  0  0 0  0 0 | 6  0 0 0 0 | 4 0 0
xx   .. .. .. ..&#x | 2  2 | 1  2  1  0 | * 32  * *  *  * | 1  3  0 0  0 0 | 3  3 0 0 0 | 3 1 0
..   .. ox .. ..&#x | 1  2 | 0  2  0  1 | *  * 48 *  *  * | 0  2  2 0  0 0 | 1  4 1 0 0 | 2 2 0
.x8/3.o .. .. ..    | 0  8 | 0  0  8  0 | *  *  * 4  *  * ♦ 1  0  0 3  0 0 | 3  0 0 3 0 | 3 0 1
.x   .. .x .. ..    | 0  4 | 0  0  2  2 | *  *  * * 48  * | 0  1  0 1  2 0 | 1  2 0 2 1 | 2 1 1
..   .. .x3.o ..    | 0  3 | 0  0  0  3 | *  *  * *  * 32 | 0  0  1 0  2 1 | 0  2 1 1 2 | 1 2 1
--------------------+------+------------+-----------------+----------------+------------+------
xx8/3oo .. .. ..&#x ♦ 8  8 | 8  8  8  0 | 1  8  0 1  0  0 | 4  *  * *  * * | 3  0 0 0 0 | 3 0 0
xx   .. ox .. ..&#x ♦ 2  4 | 1  4  2  2 | 0  2  2 0  1  0 | * 48  * *  * * | 1  2 0 0 0 | 1 2 0
..   .. ox3oo ..&#x ♦ 1  3 | 0  3  0  3 | 0  0  3 0  0  1 | *  * 32 *  * * | 0  2 1 0 0 | 1 2 0
.x8/3.o .x .. ..    ♦ 0 16 | 0  0 16  8 | 0  0  0 2  8  0 | *  *  * 6  * * | 1  0 0 2 0 | 2 0 1
.x   .. .x3.o ..    ♦ 0  6 | 0  0  3  6 | 0  0  0 0  3  2 | *  *  * * 32 * | 0  1 0 1 1 | 1 1 1
..   .. .x3.o3.o    ♦ 0  4 | 0  0  0  6 | 0  0  0 0  0  4 | *  *  * *  * 8 | 0  0 1 0 2 | 0 2 1
--------------------+------+------------+-----------------+----------------+------------+------
xx8/3oo ox .. ..&#x ♦ 8 16 | 8 16 16  8 | 1 16  8 2  8  0 | 2  8  0 1  0 0 | 6  * * * * | 2 0 0
xx   .. ox3oo ..&#x ♦ 2  6 | 1  6  3  6 | 0  3  6 0  3  2 | 0  3  2 0  1 0 | * 32 * * * | 1 1 0
..   .. ox3oo3oo&#x ♦ 1  4 | 0  4  0  6 | 0  0  6 0  0  4 | 0  0  4 0  0 1 | *  * 8 * * | 0 2 0
.x8/3.o .x3.o ..    ♦ 0 24 | 0  0 24 24 | 0  0  0 3 24  8 | 0  0  0 3  8 0 | *  * * 4 * | 1 0 1
.x   .. .x3.o3.o    ♦ 0  8 | 0  0  4 12 | 0  0  0 0  6  8 | 0  0  0 0  4 2 | *  * * * 8 | 0 1 1
--------------------+------+------------+-----------------+----------------+------------+------
xx8/3oo ox3oo ..&#x ♦ 8 24 | 8 24 24 24 | 1 24 24 3 24  8 | 3 24  8 3  8 0 | 3  8 0 1 0 | 4 * *
xx   .. ox3oo3oo&#x ♦ 2  8 | 1  8  4 12 | 0  4 12 0  6  8 | 0  6  8 0  4 2 | 0  4 2 0 1 | * 8 *
.x8/3.o .x3.o3.o    ♦ 0 32 | 0  0 32 48 | 0  0  0 4 48 32 | 0  0  0 6 32 8 | 0  0 0 4 8 | * * 1
```