Atomistic modeling of amorphous silicon carbide: an approximate first-principles study in constrained solution space

Area of Science:

• Materials Science
• Computational Chemistry
• Condensed Matter Physics

Background:

• Amorphous silicon carbide (a-SiC) is a crucial material with diverse applications.
• Accurate modeling of a-SiC's complex structure and bonding is challenging.
• Existing theoretical models often struggle to capture experimental realities.

Purpose of the Study:

• To develop a novel computational approach for generating realistic a-SiC configurations.
• To accurately model large-scale systems (1000 atoms) using first-principles simulations.
• To investigate the structural, electronic, and vibrational properties of a-SiC.

Main Methods:

• Localized basis ab initio molecular dynamics within the density functional framework.
• Construction of smart initial configurations based on experimental data.
• First-principles force field driving for energy optimization in a reduced solution space.

Main Results:

• Generation of large (1000-atom) realistic a-SiC configurations with high quantum mechanical accuracy.
• Demonstration of excellent structural and electronic properties in the simulated models.
• Identification of predominant short-range order, heteronuclear Si-C bonds, low coordination defects (5%), and chemical disorder (8%).

Conclusions:

• The developed approach successfully produces accurate, large-scale models of a-SiC.
• The simulations provide valuable insights into the fundamental properties of amorphous silicon carbide.
• This method offers a powerful tool for future materials design and discovery.