The density of states and the position of the Fermi level in the impurity band at zero temperature have been studied by Monte Carlo computer simulation over a wide range of degrees of compensation. The impurity concentration is thought to be so small that the electron states of the impurity band are localised. The density of states has a soft Coulomb gap in the vicinity of the Fermi level, and its behaviour in this region is shown to have a universal character. In the cases of extremely small and extremely close compensation the simulation results agree with the theoretical ones obtained earlier. The increase in the activation energy epsilon 1 of the band conductivity at high degrees of compensation is computed and agrees with the experimental results. However, the computed value of hopping conductivity activation energy epsilon 3 is four times as large as the experimental one.