FRAGMENT RECOGNITION IN MOLECULAR-DYNAMICS

We investigate the properties of three methods of fragment recognition in microscopic simulations of molecular dynamics. They are (a) the ea rly cluster recognition algorithm (ECRA) which looks for the most boun d partitions in phase space, (b) the minimum spanning tree in two part icle energy space (MSTE) which looks for those simply connected partit ions in which each particle is bound to, at least, one other member of the cluster to which it belongs, and (c) the standard minimum spannin g tree (MST) in configuration space. It is found that, if the objectiv e of a given calculation is to study the time evolution of properties related to the fragment distribution, the MST should be discarded, MST E results will be valid for not too short times, and ECRA results will give the most complete description of such properties.