  Recently, a novel type of a multiscale simulation, called Relative Resolution
(RelRes), was introduced. In a single system, molecules switch their resolution
in terms of their relative separation, with near neighbors interacting via
fine-grained potentials yet far neighbors interacting via coarse-grained
potentials; notably, these two potentials are analytically parameterized by a
multipole approximation. This multiscale approach is consequently able to
correctly retrieve across state space, the structural and thermal, as well as
static and dynamic, behavior of various nonpolar mixtures. Our current work
focuses on the practical implementation of RelRes in LAMMPS, specifically for
the commonly used Lennard-Jones potential. By examining various correlations
and properties of several alkane liquids, including complex solutions of
alternate cooligomers and block copolymers, we confirm the validity of this
automated LAMMPS algorithm. Most importantly, we demonstrate that this RelRes
implementation gains almost an order of magnitude in computational efficiency,
as compared with conventional simulations. We thus recommend this novel LAMMPS
algorithm for anyone studying systems governed by Lennard-Jones interactions.
