Data-Assimilated Crystal Growth Simulation for Multiple Crystalline Phases

TL;DR

This paper introduces a data-assimilated crystal growth simulation method that identifies multiple crystal phases from complex XRD patterns without prior lattice parameter knowledge, improving phase determination accuracy.

Contribution

The novel DACG simulation method enables simultaneous identification of multiple crystal structures directly from XRD data, bypassing the need for prior lattice parameter estimation.

Findings

Successfully reproduced multiple crystal structures in graphite, diamond, and silica systems.

Demonstrated effectiveness in complex XRD patterns with unknown phases.

Enhanced phase identification accuracy in crystal growth simulations.

Abstract

To determine crystal structures from an X-ray diffraction (XRD) pattern containing multiple unknown phases, a data-assimilated crystal growth (DACG) simulation method has been developed. The XRD penalty function selectively stabilizes the structures in the experimental data, promoting their grain growth during simulated annealing. Since the XRD pattern is calculated as the Fourier transform of the pair distribution function, the DACG simulation can be performed without prior determination of the lattice parameters. We applied it to C (graphite and diamond) and SiO$_2$ (low-quartz and low-cristobalite) systems, demonstrating that the DACG simulation successfully reproduced multiple crystal structures.