Fig. 5
From: Identity crisis in alchemical space drives the entropic colloidal glass transition
Alchemical Monte Carlo simulations of would-be glass-formers. Would-be glass-formers escape their identity crisis and crystallize when allowed to explore their surrounding shape space via alchemical Monte Carlo simulation. Squares indicate simulations at the glass-forming state point (αa, αc) = (0, 0.5), while circles correspond to simulations at (αa, αc) = (0.2, 0.5). Empty symbols overlaid above the shape space indicate system position at the start of Alch-MC sampling, and letters indicate system position after 20–30 million MC sweeps of vertex truncation (v), edge truncation (e), or both vertex and edge truncation (ve) sampling. System snapshots, particle shapes, pie charts of pairwise motif fractions, and bond-order diagrams31 are shown for initial and final frames of each Alch-MC simulation. Pie chart wedges are colored according to the motifs identified in Fig. 3. Wedges colored gray represent (connection type, θ) regimes that were not identified with any crystal structure. Pie chart wedges colored identically represent motifs characteristic of the same crystal structure that differ only by connection type. In those cases, the motif with face connection is always drawn second, proceeding in a counter-clockwise fashion. The hexagonal bond-order diagram resulting from edge Alch-MC sampling at (αa, αc) = (0, 0.5) is a consequence of wurtzite-like structural motifs due to the presence of stacking faults in the system. Crystalline structures resulting from edge and vertex-edge Alch-MC sampling at (αa, αc) = (0.2, 0.5) contain multiple grains and stacking faults; associated bond-order diagrams show the local environment of particles in just a single grain. In all cases shown, disordered dense fluids avoid vitrification and instead form crystals dominated by a single pairwise motif
