hexacosichoron

hexacosi- (“six hundred”) +‎ -choron (“room”), from Ancient Greek ἑξακόσιοι (hexakósioi, “six hundred”) and χώρος (khṓros, “room”).

• IPA^(key): /hɛksəɪkoʊsɪˈkoʊɹɔn/

hexacosichoron (plural hexacosichorons or hexacosichora)

1. (mathematics) A four-dimensional object analogous to an icosahedron, constructed out of six hundred tetrahedra, arranged 20 to a vertex.
   • 2007, J.R. Plaisier, L. Jiang, J.P. Abrahams, Cyclops: New modular software suite for cryo-EM‎:

     Fig. 5 shows a polar representation of 5880 rotations generated by subsampling the hexacosichoron.

   • 2011. Artur E. Ruuge, review MR2594002 (2011d:81017) of Waegell, Mordecai and Aravind, P. K., "Critical noncolorings of the 600-cell proving the Bell-Kochen-Specker theorem.", Journal of Physics A 43 (2010), no. 10, 105304

     The present paper deals with a collection of 60 rays in a 4-dimensional real vector space represented by the vertices of a hexacosichoron (i.e. a 4-dimensional analogue of the icosahedron).

     Comment: the reviewer uses the word, the reviewed paper uses 600-cell only.

   • 2012, Andrzej Katunin, Fractals based on regular convex polytopes‎, page 57:

     The hexacosichoron with an edge-length of 2φ^-1 could be constructed from the next permutations of its 120 vertices.

• 600-cell