Multinuclear NMR of CaSiO(3) glass: simulation from first-principles

Area of Science:

• Computational Materials Science
• Solid-State Chemistry
• Spectroscopy

Background:

• Amorphous calcium silicate (CaSiO3) is a key material in various applications.
• Accurate simulation of solid-state Nuclear Magnetic Resonance (NMR) spectra is crucial for understanding disordered materials.
• Existing computational methods face limitations in capturing the full complexity of amorphous structures.

Purpose of the Study:

• To develop and validate an integrated computational approach for simulating solid-state NMR spectra of amorphous CaSiO3.
• To assess the effectiveness of Kernel Estimation Density (KDE) in overcoming model size limitations.
• To establish a link between structural models and NMR spectral responses.

Main Methods:

• Coupling classical molecular dynamics (MD) simulations with density functional theory (DFT) calculations.
• Utilizing Gauge Including Projector Augmented-Wave (GIPAW) and Projector Augmented-Wave (PAW) methods for NMR parameter calculations.
• Employing Kernel Estimation Density (KDE) to refine NMR parameter distributions and simulate spectra.

Main Results:

• Generated amorphous CaSiO3 glass models using shell-model MD and DFT relaxation.
• Successfully simulated 1D and 2D NMR spectra for 29Si, 17O, and 43Ca nuclei.
• Demonstrated that KDE effectively accounts for disorder effects, improving spectral simulation accuracy.
• Achieved excellent agreement between simulated and experimental NMR spectra.

Conclusions:

• The integrated computational method accurately predicts solid-state NMR spectra for amorphous CaSiO3.
• The study validates the MD-derived structural models for CaSiO3.
• The developed approach, integrated into the fpNMR package, offers a powerful tool for analyzing disordered materials via NMR spectroscopy.