Collective mode in melting of a crystal with a face-centered lattice

The collective mechanism, which can lead to the loss of long-range order during melting of an ideal crystal with a face-centered lattice, has been studied using the molecular dynamics method. It is found that the symmetry of locations of the atoms involved in the motion is related to the crystal symmetry. The activation energy of the mechanism of the atom motion drastically decreases in the temperature-density range where the solid-liquid transition takes place.