Weakly bound PTCDI and PTCDA dimers studied by using MP2 and DFT methods with dispersion correction.

Area of Science:

• Computational Chemistry
• Materials Science
• Physical Chemistry

Background:

• Perylene derivatives like PTCDI and PTCDA are crucial in organic electronics.
• Understanding intermolecular interactions is key to controlling their solid-state properties.
• Accurate theoretical models are needed to describe van der Waals forces in these systems.

Purpose of the Study:

• To calculate potential energy curves for PTCDI and PTCDA dimers.
• To evaluate the performance of dispersion-corrected density functional theory (DFT-D) methods.
• To investigate the effect of geometrical perturbations on dimer stability.

Main Methods:

• Calculations employed MP2 and DFT-D methods with B3LYP, B97, and PBE0 functionals.
• Dispersion-correcting potentials (DCPs) were tested with PBE0 and B971 functionals.
• Analytical potential energy curves were fitted to modified Morse, Murrell-Sorbie, Buckingham, and Lennard-Jones potentials.
• Potential energy surfaces were explored at the PBE0-DCP/6-31+G(d,p) level.

Main Results:

• Two stable minima were identified for both PTCDI and PTCDA dimers.
• The study assessed the performance of various computational methods for van der Waals interactions.
• Geometrical perturbations significantly impact dimer stability.

Conclusions:

• The findings provide a detailed understanding of the stable configurations of perylene derivative dimers.
• The study validates the use of DFT-D methods for accurately describing intermolecular interactions.
• Results offer valuable data for designing and optimizing organic electronic materials based on perylene derivatives.