The polyocta­hedral silsesquioxane (POSS) 1,3,5,7,9,11,13,15-octa­phenyl­penta­cyclo­[9.5.1.1^3,9.1^5,15.1^7,13]octa­siloxane (octa­phenyl-POSS)

Solvent-free single crystals of octa­phenyl-POSS were obtained by dehydration/condensation of the tetrol Si₄O₄(Ph)₄(OH)₄. The powder pattern matches well with the experimentally measured powder pattern of commercial octa­phenyl-POSS. The geometry of the crystal is compared with that in the gas phase, and has shorter Si-O bond lengths and a broader range of Si-O-Si bond angles.