8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

P5.46Wed 711:10-14:00Cluster formation of patchy particlesGuenther Doppelbauer, 1 Dwaipayan Chakrabarti, 2 Gerhard Kahl, 1 and DavidWales 21 TU Wien, Wiedner Hauptstrasse 8-10/136, 1040, Wien, Austria2 University of Cambridge, Cambridge, United KingdomWe investigate the morphology of isolated clusters formed by colloidal particles, decorated ontheir surface by four patches of finite extent [1, 2]. Triggered by a geometric factor g, the patchesform the tips of a more or less elongated pyramid. Using basin hopping optimization tools [3],we have identified the putative equilibrium structures for clusters containing up to N = 47particles for a few selected g-values. For the tetrahedral patch arrangement ”magic cluster sizes”could be identified, which correspond to pronounced minima in the energy-per-particle curve.A closer inspection reveals that these clusters are built up by two fully bond-saturated buildingentities: a five-particle ring (either flat or bent) and a six-particle ring, with alternating verticalpositions of the particles, which in turn, are induced by the characteristic angles formed by thepatches. Investigating the disconnectivity graphs ext[4] for two particularly tightly bonded clusters(N = 10 and N = 20) reveals information about the lowest lying local minima of these clustersand the respective fastest reaction pathways between them. For patch arrangements differentfrom the tetrahedral one, building units are more difficult to identify and also play a minor role informing stable clusters.[1] J. P. K. Doye et. al., Phys. Chem. Chem. Phys. 9, 2197 (2007).[2] E. Bianchi et. al., Phys. Chem. Chem. Phys. 13, 6397 (2011).[3] D. J. Wales and J. P. K. Doye, J. Phys. Chem. A 101, 5111 (1997).[4] D. J. Wales, Energy Landscapes, Cambridge University Press, Cambridge (2003).46