Generalized model. Our approach is based on a minimalist coarse-grained model in which programmable assembly of (structurally identical) planar square-shaped units is realized through chemical specificity (or "color" ). Such building blocks are rigid bodies consisting of nine particles (with a fixed nearest neighbor distance of 1 in dimensionless LJ units), where at least one particle on their edges is "colored" (Figure ). Each colored particle, which is assigned a unique index of i, in a block can only interact with colored particles on other blocks via Lennard-Jones (LJ) potentials. Maximum affinity/attraction (of LJ strength ε) occurs solely between particles of matching colors, which allows addressability, i.e., specifying the position of a block in the target assembly. Undesired coupling between mismatched colors, or "misbinding", is penalized by its weaker strength ε' < ε. Under the defined interaction scheme, if two colored particles, i and j, are within a distance r below the LJ cutoff distance of rc = 2.3, their energy is