wˌɛɹ ɪz ðə mˈɪnɪməm bˈɛst ˈɛnɚdʒi pˈɑːsᵻbəl bᵻtwˌiːn ɹˈoʊɾeɪmɚɹ ʌv sˈaɪdtʃeɪn ænd ˌɛni ɹˈoʊɾeɪmɚɹ ˈɛks ʌv sˈaɪd tʃˈeɪn .
where  is the minimum (best) energy possible between rotamer  of sidechain  and any rotamer X of side chain .