Do the repulsive and attractive pair forces play separate roles for the   physics of liquids?
  According to standard liquid-state theory repulsive and attractive pair forces play distinct roles for the physics of liquids. This paradigm is put into perspective here by demonstrating a continuous series of pair potentials that have virtually the same structure and dynamics, although only some of them have attractive forces of significance. Our findings reflect the fact that the motion of a given particle is determined by the total force on it, whereas the quantity usually discussed in liquid-state theory is the individual pair force. 
Lasse B{\o}hling, Arno Veldhorst, Trond S. Ingebrigtsen, Nicholas P.   Bailey, Jesper S. Hansen, S{\o}ren Toxvaerd, Thomas B...
cond-mat.soft cond-mat.other cond-mat.stat-mech