Bulk structural information from density functionals for patchy particles.

Area of Science:

• Physical Chemistry
• Soft Matter Physics
• Computational Chemistry

Background:

• Classical density functional theory (DFT) is crucial for understanding fluid behavior.
• Wertheim's thermodynamic perturbation theory provides a foundation for associating particle systems.
• Accurate modeling of bulk structural properties is essential for predicting material behavior.

Purpose of the Study:

• To investigate the bulk structural properties of tetravalent associating particles using DFT.
• To compare DFT predictions with results from computer simulations.
• To evaluate the performance of different DFT functionals for these systems.

Main Methods:

• Utilizing classical density functional theory, building upon Wertheim's thermodynamic perturbation theory.
• Calculating density profiles within an effective test-particle geometry.
• Comparing theoretical results with radial distribution functions from computer simulations.

Main Results:

• A modified Yu and Wu functional based on fundamental measure theory shows accurate results for bulk properties.
• Quantitative differences arise at low temperatures due to DFT's lack of geometrical information on patch arrangements.
• The modified theory better fits simulations of the floating-bond model compared to amorphous tetrahedral network formation.
• A Segura et al. DFT approach fails to capture fundamental structural properties.

Conclusions:

• Modified DFT functionals can accurately describe bulk structural properties of tetravalent associating particles.
• Limitations exist in current DFT approaches for modeling low-temperature amorphous network structures.
• The choice of DFT functional significantly impacts the accuracy of simulation predictions.