Modeling Coronene Nanostructures: Analytical Potential, Stable Configurations and Ab Initio Energies

Abstract

Coronene is one of the basic polycyclic aromatic hydrocarbons (PAHs) used to test the reliabilty of a multidimensional potential energy surface (PES) and to assess its influence on the formation dynamics of PAH clusters with defined physical and chemical properties. We report an analytical potential energy surface for modeling the coronene− coronene interaction, whose parameters were fine-tuned on dispersion-corrected DFT estimations performed within the generalized gradient PBE approximation, that is suitable for describing molecular aggregates involving aromatic species. This model was used to build a potential function for coronene clusters (Cor n ) that was then applied in a detailed global geometry optimization study with an evolutionary algorithm. A large variety of low-energy structures were obtained for the Cor n (n = 2−15) clusters ranging from columnar-type to two-stacked in a handshake association motifs. Moreover, it was found that a transition from a single-stack columnar regime to other more complex shapes occurs at n = 6, whereas previous results based on a simpler coarse-grained potential pointed to a transition at n = 8. Geometry reoptimizations were also performed at the DFT level for the most representative low-energy structures of Cor n (n = 3−6), which confirmed the reliability of the present findings.

Noncovalent interactions between cisplatin and graphene prototypes

“…The better performance of PBE-D3(BJ) with respect to B3LYP-D3(BJ) is somewhat surprising, considering that the latter has been recently identified [25,55] as the most favorable DFT approach in terms of the accuracy/cost ratio for the description of the intermolecular interaction in representative sets of large dispersion-stabilized noncovalent complexes. However, some of the present authors have recently demonstrated [61] that the PBE-D3(BJ) level is capable of obtaining a very accurate description of molecular complexes bonded by p-p interactions, such as benzene-benzene and coronenecoronene, and the good agreement here obtained further support the picture emphasized above of a CP behavior similar to that of a molecule with a diffuse p electron cloud.…”

Nitrogen Gas on Graphene: Pairwise Interaction Potentials

“…The Improved Lennard-Jones potential has shown extensively to lower these problems via the introduction of an extra parameter controlling the R-dependence of the repulsive term [19,[37][38][39]. The ILJ potential has the following form…”

vdW‐TSSCDS—An automated and global procedure for the computation of stationary points on intermolecular potential energy surfaces

“…Methods that rely on a fit which uses a grid of nonstationary points in a physically meaningful range of intermolecular coordinates also exist in an automatic fashion. Alternatively, other approaches make use of genetic or evolutionary algorithms in combination with a large variety of different methodologies allowing for the determination of minimum energy structures of molecular clusters . However, to the best of our knowledge, these approaches are restricted to the so‐called rigid monomer approximation in which both monomers are constrained to their equilibrium geometries …”

“…Alternatively, other approaches make use of genetic or evolutionary algorithms in combination with a large variety of different methodologies allowing for the determination of minimum energy structures of molecular clusters. [77][78][79][80][81][82][83][84][85][86][87][88][89][90][91] However, to the best of our knowledge, these approaches are restricted to the so-called rigid monomer approximation in which both monomers are constrained to their equilibrium geometries. [75,76] In this work, we introduce van der Waals TSSCDS (vdW-TSSCDS), a generalization of the TSSCDS procedure which allows for the automated determination of fully relaxed stationary points on the IPES of non-covalently bound complexes.…”