Free minimizing free energy for one hard disk triangular unitcell.
A simple code for how to minimizing free energy with designed functionals in Fourier space.
Functionals derived by R.Roth et.al (Roth, Roland, Klaus Mecke, and Martin Oettel. "Communication: Fundamental measure theory for hard disks: Fluid and solid." (2012): 081101.)
For GPU speedup , see "Massively parallel GPU-accelerated minimization of classical density functional theory"
For more efficient alorigth , search "discrete inversion in iterative subspace"
For crystal-fluid properties of mixture, one can check my work "Phase diagrams and crystal–fluid surface tensions in additive and nonadditive two–dimensional hard disk mixtures" ( https://www.researchgate.net/publication/325075403_Phase_diagrams_and_crystalfluid_surface_tensions_in_additive_and_nonadditive_two-dimensional_hard_disk_mixtures or https://journals.aps.org/pre/abstract/10.1103/PhysRevE.98.012608)
My mail : shang-chun.lin@uni-tuebingen.de