ðə kɹˈɪstɐlˌaɪn stɹˈʌktʃɚɹ ɪz ʌv kjˈuːbɪk sˈiːsiəm klˈoːɹaɪd tˈaɪp æt ɹˈuːm tˈɛmpɹɪtʃɚ, bˌʌt ɪt lˈoʊɚz tə ðɪ ˌɔːɹθoːɹhˈɑːmbɪk θˈæliəm ˈaɪədˌaɪd tˈaɪp əpˌɑːn kˈuːlɪŋ, ðə tɹænsˈɪʃən tˈɛmpɹɪtʃɚ bˌiːɪŋ lˈaɪkli ɐfˈɛktᵻd baɪ ðɪ ɪmpjˈʊɹɹᵻɾiz.
The crystalline structure is of cubic caesium chloride type at room temperature, but it lowers to the orthorhombic thallium iodide type upon cooling, the transition temperature being likely affected by the impurities.