ðɪs kæn biː tɹˈɪmd sˈʌmwʌt, æt ðə kˈɔst ʌv ɐdˈɪʃənəl kəmplˈɛksᵻɾi ɪn ˌɪmplɪməntˈeɪʃən, bɪkˈʌz pˈɛɹ ˈɛnɚdʒiz ɑːɹ sɪmˈɛtɹɪkəl ænd ðə pˈɛɹ ˈɛnɚdʒi bᵻtwˌiːn ɐ ɹˈoʊɾeɪmɚ ænd ɪtsˈɛlf ɪz zˈiəɹoʊ.
This can be trimmed somewhat, at the cost of additional complexity in implementation, because pair energies are symmetrical and the pair energy between a rotamer and itself is zero.