Cluster pair correlation function of simple fluids: Energetic connectovity criteria

PUGNALONI, LUIS A.; ZARRAGOICOECHEA, GUILLERMO J.; VERICAT, FERNANDO

JOURNAL OF CHEMICAL PHYSICS

American Institute of Physics

Lugar: New York; Año: 2006 vol. 125 p. 1 - 10

0021-9606

We consider the clustering of Lennard-Jones particles by using an energetic connectivity criterion proposed long ago by Hill [J. Chem. Phys. 32, 617  (1955)] for the bond between pairs of particles. The criterion establishes that two particles are bonded  (directly connected_)  if their relative kinetic energy is less than minus their relative potential energy. Thus, in general, it depends on the direction as well as on the magnitude of the velocities and positions of the particles. An integral equation for the pair connectedness function, proposed by two of the authors [Phys. Rev. E 61, R6067 (2000)], is solved for this criterion and the results are compared with those obtained from molecular dynamics simulations and from a connectedness Percus-Yevick- type integral equation for a velocity-averaged version of Hill?s energetic criterion.