  Molecular dynamics simulations in three-dimensional copper have been
performed to quantify the void coalescence process leading to fracture. The
correlated growth of the voids during their linking is investigated both in
terms of the onset of coalescence and the ensuing dynamical interactions
through the rate of reduction of the distance between the voids and the
directional growth of the voids. The critical inter-void ligament distance
marking the onset of coalescence is shown to be approximately one void radius
in both measures.
