Abstract The noncentrosymmetric shapes of the TeO n E units ( = 3, 4, and 5) are important for nonlinear optical properties tellurite glasses (E – lone pair). An earlier diffraction work on binary (TeO 2 ) 1− x (P O 5 reported Te−O coordination numbers larger than four, which means rare case proportions units. distributions distances in these differ from those known related crystal structures. ...