# Small pyramidic swirlprism

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Small pyramidic swirlprism | |
---|---|

Rank | 4 |

Type | Scaliform |

Notation | |

Bowers style acronym | Spysp |

Elements | |

Cells | 240 pentagonal pyramids (as 120 compounds of 2) |

Faces | 600 triangles, 120 pentagons |

Edges | 600 |

Vertices | 120 |

Vertex figure | Pentagonal gyroprism |

Measures (edge length 1) | |

Circumradius | |

Volume | |

Dichoral angles | Peppy-3-peppy: Peppy-5-peppy: |

Central density | 1 |

Related polytopes | |

Army | Ex |

Regiment | Ex subregiment |

Conjugate | Great pyramidic swirlprism |

Convex core | Hecatonicosachoron |

Abstract & topological properties | |

Flag count | 9600 |

Orientable | Yes |

Properties | |

Symmetry | H_{3}●I_{2}(10), order 1200 |

Convex | No |

Nature | Tame |

The **small pyramidic swirlprism** or **spysp** is a nonconvex noble scaliform polychoron. It consists of 240 pentagonal pyramids in 120 coplanar pairs. It is notable for being *concave*, that is, it is not convex yet its entire surface is exposed.

## Vertex coordinates[edit | edit source]

Its vertex coordinates are the same as those of the general of its army, the hexacosichoron.

It can be formed by blending a small swirlprism with a faceted hexacosichoron.

Its vertex figure is the dual of the vertex figure of gisp.

## External links[edit | edit source]

- Bowers, Jonathan. "Category S4: Scaliform Swirlprisms".

- Klitzing, Richard. "spysp".