Looks like a compound of 3 tetrahedra (tet), and indeed vertices and edges both coincide by three, {3} and {6/2} coincide.

Incidence matrix according to Dynkin symbol

x3/2x3o

.   . . | 12 | 1  2 | 2 1
--------+----+------+----
x   . . |  2 | 6  * | 2 0
.   x . |  2 | * 12 | 1 1
--------+----+------+----
x3/2x . |  6 | 3  3 | 4 *
.   x3o |  3 | 0  3 | * 4

snubbed forms: β3/2x3o, x3/2β3o, β3/2β3o

x3/2x3/2o

.   .   . | 12 | 1  2 | 2 1
----------+----+------+----
x   .   . |  2 | 6  * | 2 0
.   x   . |  2 | * 12 | 1 1
----------+----+------+----
x3/2x   . |  6 | 3  3 | 4 *
.   x3/2o |  3 | 0  3 | * 4

(-x)3x3o

  .  . . | 12 | 1  2 | 2 1
---------+----+------+----
 -x  . . |  2 | 6  * | 2 0
  .  x . |  2 | * 12 | 1 1
---------+----+------+----
(-x)3x . |  6 | 3  3 | 4 *
  .  x3o |  3 | 0  3 | * 4