The effect of attractions on the local structure of liquids and colloidal fluids.

The Journal of chemical physics

PubMedID: 21198004

Taffs J, Malins A, Williams SR, Royall CP. The effect of attractions on the local structure of liquids and colloidal fluids. J Chem Phys. 2010;133(24):244901.
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.