Molecular dynamics simulations of liquid silica crystallization

Area of Science:

• Materials Science
• Computational Chemistry
• Mineral Physics

Background:

• Silica is abundant and widely utilized, but its crystallization mechanism is poorly understood.
• Simulating silica crystallization is challenging due to high energy barriers and glass-forming tendencies.

Purpose of the Study:

• To investigate the crystallization mechanism of liquid silica to beta-cristobalite.
• To develop a robust simulation method overcoming existing challenges.

Main Methods:

• Utilized metadynamics simulations with X-ray diffraction (XRD) peak intensities as collective variables.
• Employed atomic simulations to model liquid silica behavior.

Main Results:

• Achieved frequent solid-liquid transitions, indicating successful simulation control.
• Converged the free-energy surface, enabling accurate calculations.
• Estimated the melting temperature of beta-cristobalite, showing good agreement with literature values.

Conclusions:

• X-ray diffraction (XRD) peak intensities are effective collective variables for simulating silica crystallization.
• Classical nucleation theory accurately describes the nucleation mechanism in liquid silica crystallization.