Characterization of platinum nitride from first-principles calculations

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• Platinum nitrides are compounds with potential applications in various fields.
• Understanding their ground state properties is crucial for material design.
• Previous studies may have limitations in scope or computational accuracy.

Purpose of the Study:

• To systematically investigate the ground state properties of multiple platinum nitride phases.
• To compare theoretical calculations with experimental data for validation.
• To identify promising platinum nitride structures for material applications.

Main Methods:

• Utilized plane wave pseudopotential calculations within density functional theory (DFT).
• Employed both local density approximation (LDA) and generalized gradient approximation (GGA) for calculations.
• Performed lattice dynamical calculations to investigate vibrational properties.

Main Results:

• Computed equilibrium structural parameters and bulk moduli for various platinum nitride phases.
• Found excellent agreement between LDA calculations and experimental equation of state for the pyrite structure.
• Identified the pyrite phase (PtN2) as a hard material with a shear modulus of 206 GPa and a narrow indirect gap.
• Determined that fluorite and pyrite structures are dynamically stable.

Conclusions:

• The local density approximation (LDA) is essential for accurate calculations of platinum nitride properties, particularly for the pyrite phase.
• The pyrite phase of platinum nitride (PtN2) exhibits promising characteristics as a hard material.
• While fluorite and pyrite structures are dynamically stable, further refinement is needed for precise vibrational mode predictions.