Small trisoctachoron

The small trisoctachoron, or sto, is a nonconvex uniform polychoron that consists of 8 tetrahedra, 8 octahemioctahedra, and 8 truncated tetrahedra. One tetrahedron, three octahemioctahedra, and three truncated tetrahedra join at each vertex.

It also has 8 tetrahedra as pseudofacets.

Vertex coordinates
Its vertices are the same as those of its regiment colonel, the rectified tesseract.