Complex crystal structures from computational self-assembly

On the atomic scale, complex structures have been known to exist for decades and their origin, e.g., in intermetallic systems, has yet to be explained [1]. Soft matter systems have so far mostly been found to exhibit simple structures, but with a progressively versatile set of tools for creating various building blocks and interactions, the occurrence of intricate geometries is increasing (e.g., [2]). We aim to understand when and how complex structures – on multiple length scales – form, by studying the self-assembly and phase behavior of particles with tunable, isotropic pair potentials. Using the highly parallel molecular dynamics code HOOMD-blue [3], we simulate a wide range of one-component systems. We report a rich variety of crystal structures, ranging from the well-known sphere packings and other simple structure types, to crystals with giant unit cells and quasicrystals [4]. By exploring the crystal structures and observing the structure formation of these simple model systems, we aim at describing and understanding diverse experimental systems on the atomic and soft-matter length scales under the same terms.

[1] J. Dshemuchadse, D. Y. Jung, W. Steurer, Acta Crystallogr. B 67, 269–92 (2011).
[2] S. Chanpuriya, K. Kim, J. Zhang, S. Lee, A. Arora, K. D. Dorfman, K. T. Delaney, G. H. Fredrickson, F. S. Bates, ACS Nano 10, 4961–4972 (2016).
[3] J. A. Anderson, S. C. Glotzer, http://arXiv.org/abs/1308.5587 (2013). http://glotzerlab.engin.umich.edu/hoomd- blue/
[4] M. Engel, P. F. Damasceno, C. L. Phillips, S. C. Glotzer, Nature Mater. 14, 109–116 (2015)