ðə ɹˈuːt lˈæɾɪs ʌv ˈɛn hɐz dɪtˈɜːmɪnənt nˈaɪn mˈaɪnəs ˈɛn, ænd kæn biː kənstɹˈʌktᵻd æz ðə lˈæɾɪs ʌv vˈɛktɚz ɪnðɪ ˌʌnɪmˈɑːdʒuːlɚ lɔːɹˈɛntsiən lˈæɾɪs zˌiːˈɛn,wˈʌn ðæt ɑːɹ ɔːɹθˈɑːɡənəl tə ðə vˈɛktɚ wˈʌn,wˈʌn,wˈʌn,wˈʌn,...,wˈʌn θɹˈiː ʌv nˈɔːɹm ˈɛn tˈaɪmz twˈɛlv mˈaɪnəs θˈɜːɾi tˈuː ˈiːkwəlz ˈɛn mˈaɪnəs nˈaɪn.
The root lattice of En has determinant 9 − n, and can be constructed as the lattice of vectors in the unimodular Lorentzian lattice Zn,1  that are  orthogonal to the vector (1,1,1,1,...,1|3) of norm n × 12 − 32 = n − 9.