Solvent-driven symmetry of self-assembled nanocrystal superlattices-A computational study

Ananth P. Kaushik, Paulette Clancy

Research output: Contribution to journalArticlepeer-review

41 Scopus citations


The preference of experimentally realistic sized 4-nm facetted nanocrystals (NCs), emulating Pb chalcogenide quantum dots, to spontaneously choose a crystal habit for NC superlattices (Face Centered Cubic (FCC) vs. Body Centered Cubic (BCC)) is investigated using molecular simulation approaches. Molecular dynamics simulations, using united atom force fields, are conducted to simulate systems comprised of cube-octahedral-shaped NCs covered by alkyl ligands, in the absence and presence of experimentally used solvents, toluene and hexane. System sizes in the 400,000-500,000-atom scale followed for nanoseconds are required for this computationally intensive study. The key questions addressed here concern the thermodynamic stability of the superlattice and its preference of symmetry, as we vary the ligand length of the chains, from 9 to 24 CH2 groups, and the choice of solvent. We find that hexane and toluene are "good" solvents for the NCs, which penetrate the ligand corona all the way to the NC surfaces. We determine the free energy difference between FCC and BCC NC superlattice symmetries to determine the system's preference for either geometry, as the ratio of the length of the ligand to the diameter of the NC is varied. We explain these preferences in terms of different mechanisms in play, whose relative strength determines the overall choice of geometry. © 2012 Wiley Periodicals, Inc.
Original languageEnglish (US)
Pages (from-to)523-532
Number of pages10
JournalJournal of Computational Chemistry
Issue number7
StatePublished - Oct 29 2012
Externally publishedYes

Bibliographical note

KAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): KUS-C1-018-02
Acknowledgements: Contract/grant sponsor: King Abdullah University of Science and Technology (KAUST); contract/grant number: KUS-C1-018-02.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.


Dive into the research topics of 'Solvent-driven symmetry of self-assembled nanocrystal superlattices-A computational study'. Together they form a unique fingerprint.

Cite this