A First Principles Development of a General Anisotropic Potential for Polycyclic Aromatic Hydrocarbons

2010 ◽  
Vol 6 (3) ◽  
pp. 683-695 ◽  
Author(s):  
Tim S. Totton ◽  
Alston J. Misquitta ◽  
Markus Kraft
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
First Principles ◽  
Polycyclic Aromatic

High-Pressure Elastic Properties of Polycyclic Aromatic Hydrocarbons Obtained by First-Principles Calculations

2019 ◽  
Vol 57 (5) ◽  
pp. 499-508
Author(s):  
K. D. Litasov ◽  
T. M. Inerbaev ◽  
F. U. Abuova ◽  
A. D. Chanyshev ◽  
A. K. Dauletbekova ◽  
...  
Keyword(s):  
High Pressure ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Elastic Properties ◽  
Aromatic Hydrocarbons ◽  
First Principles ◽  
First Principles Calculations ◽  
Polycyclic Aromatic

scholarly journals Methanol Adsorption on Graphene

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Elsebeth Schröder
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
First Principles ◽  
Density Functional ◽  
Dispersion Interactions ◽  
High Coverage ◽  
Methanol Adsorption ◽  
Polycyclic Aromatic ◽  
Adsorption Energies ◽  
Good Agreement

The adsorption energies and orientation of methanol on graphene are determined from first-principles density functional calculations. We employ the well-tested vdW-DF method that seamlessly includes dispersion interactions with all of the more close-ranged interactions that result in bonds like the covalent and hydrogen bonds. The adsorption of a single methanol molecule and small methanol clusters on graphene is studied at various coverages. Adsorption in clusters or at high coverages (less than a monolayer) is found to be preferable, with the methanol C-O axis approximately parallel to the plane of graphene. The adsorption energies calculated with vdW-DF are compared with previous DFT-D and MP2-based calculations for single methanol adsorption on flakes of graphene (polycyclic aromatic hydrocarbons). For the high coverage adsorption energies, we also find reasonably good agreement with previous desorption measurements.

scholarly journals High-pressure elastic properties of polycyclic aromatic hydrocarbons obtained by first-principles calculations

2019 ◽  
Vol 64 (5) ◽  
pp. 460-470
Author(s):  
K. D. Litasov ◽  
T. M. Inerbaev ◽  
F. U. Abuova ◽  
A. D. Chanyshev ◽  
A. K. Dauletbekova ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
First Principles ◽  
Density Functional ◽  
Pressure Derivative ◽  
Benzene Rings ◽  
Polycyclic Aromatic ◽  
Intermolecular Distances

Crystal structure and compressibility parameters of benzene and a number of polycyclic aromatic hydrocarbons (PAHs) were calculated by first-principles methods of the density functional theory with a gradient approximation of the exchange-correlation potential in the form of PBE, taking into account the van der Waals interactions optPBE-vdW in a pressure interval of 0–20 GPa. A comparison with the experimental data for benzene, naphthalene, tetracene, and pentacene shows a high accuracy of the calculations. All studied materials have a close compressibility with the bulk modulus from 8 to 12 GPa and its pressure derivative 6.9–7.5, which consistent with a decrease in the intermolecular distances and a weak deformation of the molecules and benzene rings themselves. There is a weak dependence of the compressibility on the number of atoms (benzene rings) in the molecule or on the type of crystal structure (most PAHs have a space group P 21/a). Compounds with a large number of benzene rings, as well as a denser ring structure – cyclic (pyrene, coronene) have lower compressibility with respect to less dense PAHs (tetracene, hexacene). Some PAHs, benzene, phenanthrene, pyrene and coronene, have high-pressure modifications, but a correct description of their structures, which allows to obtain elastic modules, has not yet been made. The obtained data on PAH compressibility can be used in the development of high-temperature equations of state and calculation of the equilibrium composition of the liquid and solid components of the C-O-H system.

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