  We investigate the phase behaviour of a system of particles interacting
through the exp-6 pair potential, a model interaction that is appropriate to
describe effective interatomic forces under high compression. The
soft-repulsive component of the potential is being varied so as to study the
effect on reentrant melting and density anomaly. Upon increasing the repulsion
softness, we find that the anomalous melting features persist and occur at
smaller pressures. Moreover, if we reduce the range of downward concavity in
the potential by extending the hard core at the expenses of the soft-repulsive
shoulder, the reentrant part of the melting line reduces in extent so as it
does the region of density anomaly.

Soft Condensed Matter;Materials Science