SYMMETRY LOSS AS A CRITERION FOR CLUSTER MELTING, WITH APPLICATION TO(D-2)(13)

Continuous symmetry measures are proposed as mathematical tools to qua ntify the extent of cluster symmetry as a function of temperature. In particular, the continuous variation of symmetry as a function of temp erature is suggested as a structural criterion for the follow-up of me lting in computational studies of clusters. Numerical tests are presen ted for the (ortho-D-2)(13) cluster. A thermal distribution of configu rations for this cluster was obtained using the path integral Monte Ca rlo technique. The continuous symmetry measure selected to follow the structural changes of these nearly icosahedral structures was the degr ee of centrosymmetricity. It is found to have some conceptual advantag es and better numerical properties in comparison with the standard roo t mean square fluctuations in the intermolecular distance, commonly ap plied as a criterion of cluster melting.