title: The effect of attractions on the local structure of liquids and colloidal fluids.
abstract: We revisit the role of attractions in liquids and apply these concepts to colloidal suspensions. Two means are used to investigate the structure; the pair correlation function and a recently developed topological method. The latter identifies structures topologically equivalent to ground state clusters formed by isolated groups of 5 ≤ m ≤ 13 particles, which are specific to the system under consideration. Our topological methodology shows that, in the case of Lennard-Jones, the addition of attractions increases the system's ability to form larger (m ≥ 8) clusters, although pair-correlation functions are almost identical. Conversely, in the case of short-ranged attractions, pair correlation functions show a significant response to adding attraction, while the liquid structure exhibits a strong decrease in clustering upon adding attractions. Finally, a compressed, weakly interacting system shows a similar pair structure and topology.
authors.affiliation: School of Chemistry, University of Bristol, Bristol, BS8 1TS, United Kingdom.
authors.forename: Jade
authors.initials: J
authors.lastname: Taffs
authors.forename: Alex
authors.initials: A
authors.lastname: Malins
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Williams
authors.forename: C Patrick
authors.initials: CP
authors.lastname: Royall