  We test the validity of some widely used phenomenological criteria for the
localization of the fluid-solid transition thresholds against the phase
diagrams of particles interacting through the exp-6, inverse-power-law, and
Gaussian potentials. We find that one-phase rules give, on the whole, reliable
estimates of freezing/melting points. The agreement is ordinarily better for a
face-centered-cubic solid than for a body-centered-cubic crystal, even more so
in the presence of a pressure-driven re-entrant transition of the solid into a
denser fluid phase, as found in the Gaussian-core model.
