Critical points, phase transitions and water-like anomalies for an isotropic two length scale potential with increasing attractive well

Molecular Dynamic and Monte Carlo studies are performed in a system of particles interacting through core-softened (CS) potential, composed by two length scales: a repulsive shoulder at short distances and the another a variable scale, that can be repulsive or strongly attractive depending on the parameters used. The system show water-like anomalous behavior. The density, diffusion and structural anomalous regions in the pressure versus temperature phase diagram shrink in pressure as the system becomes more attractive. The transition appears with the increase of the attraction well. We found that the liquid-gas phase transition is Ising-like for all the CS potentials and its critical temperature increases with the increase of the attraction. No Ising-like behavior for the liquid-liquid phase transition was detected in the Monte Carlo simulations what might be due to the presence of stable amorphous phases.