ɐ tˈuː θˈaʊzənd ˈeɪt stˈʌdi baɪ lˈuː ˈɛt ˈæl. ʃˈoʊd ðæt lˌæ tˈuː sˈiː sˈɛvənti tˈuː duːnˌɑːt ɐdhˈɪɹ tə ðɪ ˈaɪsəlˌeɪɾᵻd pˈɛntæɡən ɹˈuːl ˌaɪpˌiːˈɑːɹ, bˌʌt hɐz tˈuː pˈɛɹz ʌv fjˈuːzd pˈɛntæɡənz æɾ ˈiːtʃ pˈoʊl ʌvðə kˈeɪdʒ ænd ðætðə tˈuː lˌæ ˈæɾəmz ɹᵻsˈaɪd klˈoʊs tə ðə tˈuː fjˈuːzdpˈɛntæɡən pˈɛɹz.
A 2008 study by Lu et al. showed that La2C72 do not adhere to the isolated pentagon rule (IPR), but has two pairs of fused pentagons at each pole of the cage and that the two La atoms reside close to the two fused-pentagon pairs.