# Naphthalene crystal shape prediction from molecular dynamics simulations

## TL;DR

This study uses advanced molecular dynamics simulations with enhanced sampling techniques to accurately predict the steady state crystal shape of naphthalene, aligning well with experimental observations.

## Contribution

It introduces a novel simulation approach combining constant supersaturation and Well-Tempered Metadynamics to predict crystal shapes from solution.

## Key findings

- Predicted crystal shape is a rhombic prism consistent with experiments.
- Different crystal faces grow via distinct nucleation mechanisms.
- Simulation methods effectively capture crystal growth dynamics.

## Abstract

We used molecular dynamics simulations to predict the steady state crystal shape of naphthalene grown from ethanol solution. The simulations were performed at constant supersaturation by utilizing a recently proposed algorithm [Perego et al., J. Chem. Phys., 142, 2015, 144113]. To bring the crystal growth within the timescale of a molecular dynamics simulation we applied Well-Tempered Metadynamics with a spatially constrained collective variable, which focuses the sampling on the growing layer. We estimated that the resulting steady state crystal shape corresponds to a rhombic prism, which is in line with experiments. Further, we observed that at the investigated supersaturations, the $\{00\bar{1}\}$ face grows in a two step two dimensional nucleation mechanism while the considerably faster growing faces $\{1\bar{1}0\}$ and $\{20\bar{1}\}$ grow new layers with a one step two dimensional nucleation mechanism.