For a protein of length  with  rotamers per residue, the energy at the current iteration is described by the following expression.
fɚɹə pɹˈoʊtiːn ʌv lˈɛŋθ wɪð ɹˈoʊɾeɪmɚz pɜː ɹˈɛsɪdˌuː, ðɪ ˈɛnɚdʒi æt ðə kˈɜːɹənt ˌɪɾɚɹˈeɪʃən ɪz dᵻskɹˈaɪbd baɪ ðə fˈɑːloʊɪŋ ɛkspɹˈɛʃən.