We
examine the performance of the general AMBER force field (GAFF)
and the CHARMM general force field (CGenFF) within the context of
capturing the liquid–vapor saturation properties of naphthalene
derivatives. Molecular simulation is employed to construct phase diagrams
for naphthalene, tetralin, trans-decalin, quinolone,
1-methylnaphthalene, 1-naphthol, indole, benzo[b]furan,
and benzo[b]thiophene over a range of temperatures
that spans from room temperature to the critical point. A general
histogram-based approach introduced by Rane and co-workers (J. Chem. Theory Comput.
2013, 9, 2552) is used to calculate saturated densities, vapor pressures,
and enthalpies of vaporization. Results for GAFF and CGenFF are compared
to experimental data, available correlations, and literature results
for the transferable potentials for phase equilibria force field (TraPPE).
GAFF and CGenFF provide reasonable descriptions for the saturation
properties of the naphthalene derivatives studied. Specifically, GAFF
and CGenFF capture the critical temperature to within average errors
of 5.6 and 6.3%, respectively, and the boiling temperature to within
average errors of 4.0 and 4.4%, respectively. The models generally
produce estimates of the critical temperature and boiling temperature
that are low relative to experiment. The two models provide a relatively
consistent description of the six molecules studied containing two
fused six-membered rings, whereas their description of the three molecules
examined containing fused five- and six-membered rings often differs
appreciably. In terms of an overall comparison, our results do not
indicate that one force field clearly outperforms the other.