A new interatomic potential, tuned to calculate the energies and structures of nanoscale silica, is presented. The potential parameters for Si-O, O-O, and Si-Si interactions were fitted using a training set consisting of a number of (SiO2)(n) (n less than or equal to 5) nanocluster structures calculated using density functional theory (DFT). Testing of the potential was performed using 25 different (SiO2)(7) nanoclusters. For nanocluster energies and structures, the new potential outperforms other similar potentials widely used for bulk silica and also performs favourably compared with semi-empirical methods. In addition, using a genetic algorithm with the new potential, two novel (SiO2)(7) ground state structures are proposed. (C) 2003 Elsevier B.V. All rights reserved.