  This work presents a consistent formulation of the structural
phase-field-crystal model of substitutional binary alloys that allows for the
description phases of unequal densities, a key feature in solidification. We
further develop the dynamics of the model to be consistent with conserved
Langevine dynamics in the true governing species densities. Additionally, this
work expands on the ability to control pressure, so far only implemented in
pure materials, to binary alloys by improving the control system that controls
pressure from previous work. We study the equilibrium properties of the new
model, and demonstrate that control of pressure can drive various kinematic
microscopic processes in materials such as grain boundary pre-melting, phase
instability, and grain or inter-phase boundary motion.
