Based upon computational considerations, a novel synthetic route towards well-defined stoichiometric silica nanoclusters is proposed. Density-functional calculations demonstrate the viability of a route based upon siloxane cage thermolysis, while, molecular dynamics calculations were performed to test the stability of the cages formed. We predict for small siloxane cages defect-rich structures to be the main product, while, for larger siloxane cages fully coordinated silica nanoclusters iso-structural to their precursor to be formed. Overall, thermolysis of siloxane cages is expected to present a viable route towards specific types of metastable yet, well-defined silica nanoclusters, not obtainable by less targeted cluster generation methods. (C) 2004 Elsevier B.V. All rights reserved.