Crystal nucleation for a model of globular proteins

TL;DR

This paper investigates a continuum model of globular protein nucleation, revealing limitations of classical nucleation theory near critical points and providing an approximate analytic description of nucleating droplets.

Contribution

It demonstrates the failure of classical nucleation theory in certain regions and offers an analytic approach to describe nucleating crystal droplets in globular proteins.

Findings

Classical nucleation theory is invalid near the metastable critical point.

Classical nucleation theory is invalid close to the liquidus line.

An approximate analytic solution for nucleating droplets is presented.

Abstract

A continuum model of globular proteins proposed by Talanquer and Oxtoby (J. Chem. Phys. vol. 109, p. 223 (1998)) is investigated numerically, with particular emphasis on the region near the metastable fluid-fluid coexistence curve. Classical nucleation theory is shown to be invalid not only in the vicinity of the metastable critical point but also close to the liquidus line. An approximate analytic solution is also presented for the shape and properties of the nucleating crystal droplet.