wˌaɪl kˈuːlɪŋ fɹʌm ɪts hˈaɪtˈɛmpɹɪtʃɚ, hˈaɪɚ sˈɪmətɹi fˈeɪz spˈeɪs ɡɹˈuːp sˌiːˌɛmsˌiːˈɛm, hˈæʃ sˈɪksti θɹˈiː, ˌɛsˈɛn sˈiː ˌʌndɚɡˈoʊz ɐ dɪsplˈæsɪv ʃˈɪɹ fˈeɪz tɹænsˈɪʃən æt tˈɪldə sˈɛvənhˈʌndɹɪd fˈɪfti ˈeɪthˈʌndɹɪd kˈeɪ, ɹɪzˈʌltɪŋ ɪn ɐ lˈoʊɚ sˈɪmətɹi pˌiːˌɛnˌɛmˈeɪ hˈæʃ sˈɪksti tˈuː spˈeɪs ɡɹˈuːp.
While cooling from its high-temperature, higher symmetry phase (space group Cmcm, #63), SnSe undergoes a displacive (shear) phase transition at ~750–800 K, resulting in a lower symmetry Pnma (#62) space group.