  In this study, we incorporate configuration mapping between simulation
ensembles into the successive interpolation of multistate reweighting (SIMR)
method in order to increase phase space overlap between neighboring simulation
ensembles. This significantly increases computational efficiency over the
original SIMR method in many situations. We use this approach to determine the
coexistence curve of face-centered cubic-hexagonal close-packed Lennard-Jones
spheres using direct molecular dynamics and SIMR. As previously noted, the
coexistence curve is highly sensitive to the treatment of the van der Waals
cutoff. Using a cutoff treatment, the chemical potential difference between
phases is moderate and SIMR quickly finds the phase equilibrium lines with good
statistical uncertainty. Using a smoothed cutoff results in nonphysical errors
in the phase diagram, while the use of particle mesh Ewald for the dispersion
term results in a phase equilibrium curve that is comparable with previous
results. The drastically closer free energy surfaces for this case test the
limits of this configuration mapping approach to phase diagram prediction.
