  A phase-field crystal model based on the density-field approach incorporating
high-order interparticle direct correlations is developed to study
vapor-liquid-solid coexistence and transitions within a single continuum
description. Conditions for the realization of the phase coexistence and
transition sequence are systematically analyzed and shown to be satisfied by a
broad range of model parameters, demonstrating the high flexibility and
applicability of the model. Both temperature-density and temperature-pressure
phase diagrams are identified, while structural evolution and coexistence among
the three phases are examined through dynamical simulations. The model is also
able to produce some temperature and pressure related material properties,
including effects of thermal expansion and pressure on equilibrium lattice
spacing, and temperature dependence of saturation vapor pressure. This model
can be used as an effective approach for investigating a variety of material
growth and deposition processes based on vapor-solid, liquid-solid, and
vapor-liquid-solid growth.
