Fundamental-measure density functional for the fluid of aligned hard hexagons: Further insights in fundamental measure theory.

摘要: In this article we obtain a fundamental measure functional for the model of aligned hard hexagons in plane. Our aim is not just to provide an admittedly academic model, but investigate structure theory. A has similarities with disk model. Both share ``lost cases,'' i.e. admit configurations three particles which there pairwise overlap triple overlap. These are known be problematic functionals, able capture their contribution correctly. This failure lies inability these functionals yield correct low density limit third order direct correlation function. Here derive by projecting cubes on plane $x+y+z=0$. The dimensional crossover behavior permits us follow strategy. cubes, however, does have lost cases, so neither had resulting hexagons. latter exhibits, fact, peculiar as compared one disks. It depends uniparametric family weighted densities through additional term appearing Apart from studying freezing system, discuss implications further developments