“…For example, Seymour and Provatas [39] approximated the three-point direct correlation function as the product of two-point direct correlations to model structures with a specific bond angle, such as triangular, honeycomb, or square, and Kocher and Provatas [40] used both three-and four-point direct correlations to model vapor-liquid-solid transitions. Alternatively, Alster et al [41] expanded the three-point correlation function in terms of Legen-dre polynomials in Fourier space and constructed various crystalline phases (including the ABX 3 perovskite structure) from their PFC model. Recently, we developed a general PFC formulation to incorporate any multipoint direct correlations satisfying the condition of rotational invariance [35], from which effects of bond-angle dependency and adjustment can be achieved through the four-point correlation, and a variety of 2D and 3D crystal structures, such as 3D diamond cubic phase and 2D rhombic or 3D simple monoclinic structure with tunable bond angles, can be stabilized.…”