Geometric magic numbers of sodium clusters: Interpretation of the melting behaviour E. G. Noya, J. P.K. Doye, D. J. Wales and A. Aguado Eur. Phys. J. D, 43 1-3 (2007) 57-60 Published online: 24 May 2007 DOI: 10.1140/epjd/e2007-00092-x