ˈiːtʃ pˈɛɹ ˈɛnɚdʒi mˈeɪtɹɪks bᵻtwˌiːn tˈuː pəzˈɪʃənz ænd , fɔːɹ dɪskɹˈiːt ɹˈoʊɾeɪmɚz æɾ ˈiːtʃ pəzˈɪʃən, ɹᵻkwˈaɪɚz ɐ mˈeɪtɹɪks.
Each pair energy matrix between two positions  and , for  discrete rotamers at each position, requires a  matrix.