Phase diagram and structural diversity of the densest binary sphere packings

TL;DR

This paper maps the phase diagram of the densest binary sphere packings across various sphere size ratios and concentrations, revealing many previously unknown optimal arrangements.

Contribution

It provides the most comprehensive phase diagram of densest binary sphere packings using an advanced algorithm, discovering numerous new dense packings.

Findings

Many new densest packings identified

Phase diagram mapped across alpha-x plane

Algorithm effectively finds optimal packings

Abstract

The densest binary sphere packings have historically been very difficult to determine. The only rigorously known packings in the alpha-x plane of sphere radius ratio alpha and relative concentration x are at the Kepler limit alpha = 1, where packings are monodisperse. Utilizing an implementation of the Torquato-Jiao sphere-packing algorithm [S. Torquato and Y. Jiao, Phys. Rev. E 82, 061302 (2010)], we present the most comprehensive determination to date of the phase diagram in (alpha,x) for the densest binary sphere packings. Unexpectedly, we find many distinct new densest packings.