SOLID-LIQUID CLUSTER RECOGNITION IN HETEROGENEOUS SYSTEMS

Criteria are presented which enable the differentiation between the extent of solid-like and liquid-like character in a heterogenous system on a per atom basis. Such criteria are developed for two different interatomic potentials, the Stillinger-Weber model for group IV semiconductors and the Lennard-Jones model for insulators. For the Stillinger-Weber potential model, three criteria are presented: one based on the coordination number of nearest neighbors, one based on the three-body energy, and one based on the angular positions (spatial arrangements) of neighbors. For the Lennard-Jones model an angular criterion is used. The difficulties associated with the assignation of interfacial atoms (those with partial solid and partial liquid character) are discussed. The effectiveness of these criteria for both models is tested by application to the identification of solid-like nuclei in the melt.