Structure, dynamics and melting of 19-atom double icosahedral silver cluster

In this paper, the structural and dynamical properties of the 19-atom double icosahedral silver cluster are studied by using the classical molecular dynamics. It is found that the melting of the 19-atom cluster starts with the migrations of the surface atoms. The surface atoms can interchange positions with each other atoms through three ways. The first and second ways involve with only part of the surface atoms. The third way can involve the surface atoms at all symmetrical positions. With the increase of temperature, the inner atoms can hop onto the surface of the cluster and the position interchange between the surface atoms and the inner atoms can be realized. With further increase of temperature, the isomerization of the cluster becomes frequent and the motion of the atoms of the cluster becomes more and more disordered. When the temperature reaches the value corresponding to the second peak of the heat capacity, the solid cluster turns into the fully melted state.