  Using molecular dynamic simulations we study a system of particles
interacting through a continuous core-softened potentials consisting of a hard
core, a shoulder at closest distances and an attractive well at further
distance. We obtain the pressure-temperature phase diagram of of this system
for various depths of the tunable attractive well. Since this is a two length
scales potential, density, diffusion and structural anomalies are expected. We
show that the effect of increasing the attractive interaction between the
molecules is to shrink the region in pressure in which the density and the
diffusion anomalies are present. If the attractive forces are too strong,
particle will be predominantly in one of the two length scales and no density
of diffusion anomaly is observed. The structural anomalous region is present
for all the cases.
