  The simplest statistical-mechanical model of crystalline formation (or alloy
formation) that includes electronic degrees of freedom is solved exactly in the
limit of large spatial dimensions and infinite interaction strength. The
solutions contain both second-order phase transitions and first-order phase
transitions (that involve phase-separation or segregation) which are likely to
illustrate the basic physics behind the static charge-stripe ordering in
cuprate systems. In addition, we find the spinodal-decomposition temperature
satisfies an approximate scaling law.
