Open AccessStructures and Energetics of Neutral and Cationic Pyrene Clusters
Author(s) -
Léo Dontot,
Fernand Spiegelman,
Mathias Rapacioli
Publication year - 2019
Publication title -
the journal of physical chemistry. a/the journal of physical chemistry. a.
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.756
H-Index - 235
eISSN - 1520-5215
pISSN - 1089-5639
DOI - 10.1021/acs.jpca.9b07007
Subject(s) - trimer , cationic polymerization , adiabatic process , chemistry , density functional theory , chemical physics , binding energy , molecular physics , atomic physics , dimer , molecule , ion , ionization , computational chemistry , physics , thermodynamics , organic chemistry
The low energy structures of neutral and cationic pyrene clusters containing up to seven molecules are searched through a global exploration scheme combining parallel tempering Monte Carlo algorithm and local quenches. The potential energies are computed at the density functional based tight binding level for neutrals and configuration interaction density functional based tight binding for cations in order to treat properly the charge resonance. New simplified versions of these schemes are also presented and used during the global exploration. Neutral clusters are shown to be made of compact assemblies of sub-blocs containing up to three units whereas cations present a charged dimer or trimer core surrounded by neutral units. The structural features of the clusters are analyzed and correlated for the cation with the charge distribution. The stability of clusters is also discussed in terms of cohesive and evaporation energies. Adiabatic and vertical ionization potentials are also discussed.