We perform ab initio band structure calculations within density functional theory using an exact exchange formalism and a local density approximation for correlations. Ensemble Monte Carlo simulations consider all relevant scattering mechanisms including a realistic impact ionization rate. This full-band ensemble Monte Carlo method is applied to study the high-field electron transport. Results can be given for the total electron–phonon scattering rate, the drift velocity, the mean kinetic energy, the valley occupations and the ionization coefficient. We show here exemplary results for the wide band-gap materials ZnS and GaN.