When the elongated square pyramid with unit edge lengths (i.e., an equilateral obelisk) is truncated by a plane passing through opposite corners of its square base and the apex of the pyramid, it bisects the original solid and gives a half-obelisk that may be termed a hemiobelisk.
It is implemented in the Wolfram Language as PolyhedronData["Hemiobelisk"].
This solid is one of two having 7 vertices, 11 edges, and 7 faces (the other being the hemicube) and is an example of one of the 7 topological classes of concave hexahedron.
When constructed from a unit elongated square pyramid, the solid consists of two unit squares, an isosceles
right triangle with unit base lengths. two unit equilateral triangles, and an
isosceles right pentagon with base length 
and all other sides of length 1.
The skeleton of the hemiobelisk is the hemiobelisk graph.
