Structural and vibrational properties of solid nitromethane under high pressure by density functional theory.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Computational Chemistry

Background:

• Nitromethane is a versatile chemical compound with applications in various fields.
• Understanding its behavior under extreme conditions, such as high pressure, is crucial for safety and material design.

Purpose of the Study:

• To investigate the structural, vibrational, and electronic properties of solid nitromethane under hydrostatic pressure up to 20 GPa.
• To determine the bulk modulus and its pressure derivative.
• To analyze the pressure-induced changes in electronic band gap and vibrational frequencies.

Main Methods:

• Density Functional Theory (DFT) calculations were employed.
• Analysis of cell volume, lattice constants, and molecular geometry under pressure.
• Fitting of the volume-pressure relation to obtain bulk modulus (B0) and its pressure derivative (B0').
• Computation of vibrational frequencies for internal and lattice modes.

Main Results:

• Theoretical predictions for structural and electronic properties were obtained.
• Calculated bulk modulus and its pressure derivative were determined.
• Pressure-dependent vibrational frequencies were computed and analyzed.
• Comparison with available experimental data was performed.

Conclusions:

• The study provides a comprehensive theoretical understanding of solid nitromethane under high pressure.
• The results offer insights into the material's response to hydrostatic loading.
• The findings can inform the safe handling and application of nitromethane in high-pressure environments.