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<=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 out-performs 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.