Abstract. Results of modeling of phases and phase transition in the water octamer with TIP4P interaction potential from molecular point of view are presented. In the study the molecular dynamics method was applied. The advantage of using the dynamical characteristics of individual molecules in the cluster is shown, particularly, the distribution of the potential energy, to identify the phase of the cluster. The criteria for solid like and liquid like phases in the octamer are suggested and the connection isomer’s structures with dynamics are discussed. The role of different types of H-bonds (DDA- and DAA-type) in dynamical characteristics of the cluster is clarified.

 

Key words: water clusters, structural transformation, isomerization, melting, molecular dynamics simulation, microcanonical ensemble.