Assessing the performance of density functional theory in optimizing molecular crystal structure parameters.

Area of Science:

• Computational Chemistry
• Materials Science
• Solid-State Physics

Background:

• Accurate prediction of molecular crystal structures is crucial for understanding material properties.
• Density functional theory (DFT) is a powerful tool for electronic structure calculations.
• Intermolecular interactions, such as hydrogen bonding and dispersion forces, significantly influence crystal packing.

Purpose of the Study:

• To evaluate the performance of plane-wave DFT calculations for molecular crystal structure prediction.
• To assess the reliability of structural information for crystals dominated by hydrogen bonding or dispersion interactions.
• To compare DFT-computed structures with experimental data from the Cambridge Structural Database.

Main Methods:

• Plane-wave density functional theory (DFT) calculations were employed.
• The Perdew-Burke-Ernzerhof (PBE) functional was used in conjunction with the Tkatchenko-Scheffler (TS) dispersion correction.
• Structural parameters including crystal packing, unit-cell dimensions, contact distances, and hydrogen-bond lengths were analyzed.

Main Results:

• The PBE functional combined with the TS dispersion correction accurately reproduced molecular crystal structures.
• The method demonstrated reliability in optimizing both atomic positions and unit-cell parameters simultaneously.
• Calculated structures showed good agreement with experimental data in terms of packing, volume, shape, and specific distances.

Conclusions:

• Plane-wave DFT, specifically the PBE+TS approach, is a reliable method for optimizing molecular crystal structures.
• This computational approach is effective for crystals governed by hydrogen bonding and dispersion interactions.
• The study validates the use of PBE+TS for accurate prediction of crystal structures and properties.