Dear all,
I wonder if I can ask a more general question about r_cut for dpd, if possible.
In the user-guide, it is written: "When using a Lennard-Jones interaction, r_cut = 2^(1/6) σ is a good value to choose, so that the thermostat acts on the relative velocities between nearest neighbor particles. Larger cutoffs including next nearest neighbors or even more are unphysical."
My questions are:
(1) Does the suggested cut-off depends on the cut-off radius of the Lennard-Jones potential? In other words, the Lennard-Jones potential should be truncated at the minimum?
(2) Why larger cut-offs are unphysical? Does this result from the physical imagination that only neighboring spheres have friction? Or, the shape of potentials are important in this reasoning?
Please apologize me for interrupting again.
Many thanks in advance,
Narges Nikoofard