haʊˈɛvɚ, æt tˈɪldə sˈɛvənhˈʌndɹɪd fˈɪfti kˈeɪ, ɪɾ ˌʌndɚɡˈoʊz ɐ fˈeɪz tɹænsˈɪʃən ðæt ɹɪzˈʌlts ɪn ɐ hˈaɪɚ sˈɪmətɹi sˌiːˌɛmsˌiːˈɛm stɹˈʌktʃɚ.
However, at ~750 K, it undergoes a phase transition that results in a higher symmetry Cmcm structure.