# Simulations of Crystal Nucleation from Solution at Constant Chemical Potential

## TL;DR

This paper introduces a molecular dynamics simulation method that maintains constant chemical potential to accurately study crystal nucleation from solutions, avoiding artifacts caused by solution depletion in traditional methods.

## Contribution

The authors adapt the constant chemical potential molecular dynamics approach to simulate nucleation, enabling precise determination of nucleus size and nucleation rates at fixed supersaturation.

## Key findings

- Successfully applied to sodium chloride nucleation from aqueous solution.
- Able to determine nucleation rates at constant supersaturation.
- Avoids artifacts from solution depletion in canonical ensemble simulations.

## Abstract

A widely spread method of crystal preparation is to precipitate it from a supersaturated solution. In such a process, control of solution concentration is of paramount importance. Nucleation process, polymorph selection, and crystal habits depend crucially on this thermodynamic parameter. When performing simulations in the canonical ensemble as the crystalline phase is deposited the solution is depleted of solutes. This unavoidable modification of the thermodynamic conditions leads to significant artifact. Here we adopt the idea of the constant chemical potential molecular dynamics approach of Perego et al. [J. Chem. Phys. 2015, 142, 144113] to the study of nucleation. Our method allows determining the crystal nucleus size and nucleation rates at constant supersaturation. As an example we study the homogeneous nucleation of sodium chloride from its supersaturated aqueous solution.