Densest vs. jammed packings of 2D bent-core trimers

Abstract

We identify the maximally dense lattice packings of tangent-disk trimers with fixed bond angles ($\theta = \theta_0$) and contrast them to both their nonmaximally-dense-but-strictly-jammed lattice packings as well as the disordered jammed states they form for a range of compression protocols. While only $\theta_0 = 0,\ 60^\circ,\ \rm{and}\ 120^\circ$ trimers can form the triangular lattice, maximally-dense maximally-symmetric packings for all $\theta_0$ fall into just two categories distinguished by their bond topologies: half-elongated-triangular for $0 < \theta_0 < 60^\circ$ and elongated-snub-square for $60^\circ < \theta_0 < 120^\circ$. The presence of degenerate, lower-symmetry versions of these densest packings combined with several families of less-dense-but-strictly-jammed lattice packings act in concert to promote jamming.