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We apply the semiempirical nonlocal pseudopotential method to the investigation of prospects for direct carrier multiplication (DCM) in neutral and negatively charged CdSe nanocrystals. In this process, known in the bulk as impact ionization, a highly excited carrier transfers, upon relaxation to the band edge, its excess energy Δ to a valence electron, promoting it across the band gap and thus creating two excitons from one. For excess energies just a few meV above the energy gap E_g (the DCM threshold), we find the following:  (i) DCM is much more efficient in quantum dots than in bulk materials, with rates of the order of 10¹⁰ s^-1. In conventional bulk solids, comparable rates are obtained only for excess energies about 1 eV above E_g. (ii) Unlike the case in the bulk, in both neutral and charged nanocrystals the DCM rate is not an increasing function of the excess energy but oscillates as Δ moves in and out of …