“…It is well known that for Fermi energy E F ≈ 0, the Ando model exhibits a metalinsulator transition as a function of disorder at W = W c ≈ 5.8 [6,12]. The critical exponent for various 2d systems with symplectic symmetry has been estimated in numerous works using different numerical methods [12,15,20,21,22,14,23], leading to rather inconsistent results. The critical conductance was studied in [24].…”