Fig. 4.

Crystallization of a layered crystal (oF244) via fiber formation. Hard pentagonal bipyramids (PBPs) self-assemble into a layered crystal (oF244) at constant packing density $\varphi =0.58$0. (A) In the early stage of crystallization, hard PBPs separate into an LDF (transparent blue) and an HDF that consists of fiber-like motifs (light green). (B) The obtained crystal consists of layers of parallel fibers (dark green). (C) A cross-section of the crystal phase shows that a crystal layer (dark green) and a weakly ordered layer (yellow) alternate within the crystal. (D) The radial distribution function $g\left(r\right)$ of the crystal layers, the weakly ordered layers, and the LDF. (E) A fiber-type prenucleation motif (Left) found in the HDF. (Right) Centers of PBPs and bonds (gray). (F) Part of a crystal layer with PBP representation (Left) and its centers (Right). (G) A density plot of particle centers for a cross-section of the crystal averaged over $200\times {10}^6$ Monte Carlo sweeps. See Movie S3 for the movement of particles in each layer. (H) Equation of state of hard PBPs. Each data point is obtained by a single isobaric Monte Carlo run initialized in a disordered starting configuration for compression (black line) and initialized in an HDF configuration for decompression (blue line). (I) Diffusivity of the 2 fluids near the LDF-to-HDF transition.