Clusters of polycyclic aromatic hydrocarbons (PAHs) are essential components of soot and may concentrate a significant fraction of carbon matter in the interstellar medium. In this contribution, coarse-grained potentials are parameterized using all-atom reference data to model PAH molecules, such as coronene (C24H12) or circumcoronene (C54H18), and their aggregates. Low-energy structures of pur...

Assuming a delta pulse excitation, quantum wavepackets are propagated on the excited state manifold in energy range from 3.4-5.0 eV for coronene and 2.4-3.5 circumcoronene to study...

let g be a simple graph with vertex set v(g) {v1,v2 ,...vn} . for every vertex i v , ( ) i  vrepresents the degree of vertex i v . the h-th order of randić index, h r is defined as the sumof terms1 2 11( ), ( )... ( ) i i ih  v  v  vover all paths of length h contained (as sub graphs) in g . inthis paper , some bounds for higher randić index and a method for computing the higherrandic ind...

A method for the calculation of the hyper–Wiener index (WW ) of a benzenoid system B is described, based on its elementary cuts. A pair of elementary cuts partitions the vertices of B into four fragments, possessing nrs , r, s = 1, 2 vertices. WW is equal to the sum of terms of the form n11 n22 + n12 n21 . The applicability of the method is illustrated by deducing a general expression for WW of...

Let G be a simple graph with vertex set V(G) {v1,v2 ,...vn} . For every vertex i v , ( ) i  v represents the degree of vertex i v . The h-th order of Randić index, h R is defined as the sum of terms 1 2 1 1 ( ), ( )... ( ) i i ih  v  v  v  over all paths of length h contained (as sub graphs) in G . In this paper , some bounds for higher Randić index and a method for computing the higher R...

We study the interaction of circumcoronene molecule C54H18 with cobalt in the form of atoms, dimers and clusters of four atoms. We find that the cobalt atom prefers to be on a hollow site in the edge zone. The cobalt dimer is bonded perpendicularly to another different hollow site in the edge zone. The Co4 cluster adopts a tetrahedral shape with a face parallel to circumcoronene, placing each o...

The geometries, electronic and magnetic properties of neutral and negatively charged Mn(coronene)m (M = V and Ti; n, m = 1, 2) complexes were investigated using density functional theory. The results show that one V or Ti atom prefers to occupy the η(6)-site in M(coronene)(0/-) complexes and to be sandwiched between the two coronene molecules in M(coronene)2(0/-) complexes. Two metal atoms alwa...

Stability of the π-π stacking interactions in the Ben||substituted-coronene and HFBen||substituted-coronene complexes was studied using the computational quantum chemistry methods (where Ben and HFBen are benzene and hexaflourobenzene, || denotes π-π stacking interaction, substituted-coronene is coronene molecule which substituted with four X groups, and X= NH2, CH3, OH, H, F, CF3, CN and NO). ...