the fullerene structures of c20cage and bowl,c20h10 and their n-doped structures as c20cage nh,c20bowl nh, c20h10nh, c20h10n and their isomers are optimized using the mpw1pw91/6-31g level of the theory. magnetic shielding tensors of 14n and 13c atoms are calculated by the same level of the theory. results show that doping an n atom on fullerenes affects differently on the chemical shielding of ...

the b3lyp/6-31++g** density functional calculations were used to obtain minimum geometries and interaction energies between the molecular hydrogen and nanostructures of fullerenes, c20 (cage), c20 (bowl), c19si (bowl, penta), c19si (bowl, hexa). the h2 molecule is set as adsorbed in the distance of 3å at vertical position from surface above the pentagonal and hexagonal sites of nanostructures. ...

In this study, the performance of fullerene (C20) and boron nitride cage (B12N12) as a sensing material for detection of proline was evaluated by density functional theory. For this purpose, the structures of proline, C20, B12N12 and the derived products from the proline adsorption on the surface of nanostructures were optimized geometrically. Then, IR and Frontier molecular orbital calculation...

The B3LYP/6-31++G** density functional calculations were used to obtain minimum geometries and interaction energies between the molecular hydrogen and nanostructures of fullerenes, C20 (cage), C20 (bowl), C19Si (bowl, penta), C19Si (bowl, hexa). The H2 molecule is set as adsorbed in the distance of 3Å at vertical position from surface above the pentagonal and hexagonal sites of nanostructures. ...

Infrared (IR) and ultraviolet (UV) spectroscopic analysis of eight structural isomers of C20 carbon nanostructures, i.e. ring, tadpole, bow-tie, dumb-bell, spiro, propellane, bowl and cage, were performed at different levels of theory including semi-empirical (AM1 and PM3), Hartree-Fock (HF/6-31++G, 6-31++G**) and density functional theory (B3LYP/6-31++G, 6-31++G**). A broad range of IR spectra...

High-level ab initio calculations have been carried out to reexamine relative stability of bowl, cage, and ring isomers of C(20) and C(20)(-). The total electronic energies of the three isomers show different energy orderings, strongly depending on the hybrid functionals selected. It is found that among three popular hybrid density-functional (DF) methods B3LYP, B3PW91, PBE1PBE, and a new hybri...

An atom trapped in a crystal vacancy, metal cage, or fullerene might have many immediate neighbors. Then, the familiar concept of valency even coordination number seems inadequate to describe environment that atom. This difficulty terminology is illustrated here by four systems: H atoms tetragonal-pyramidal rhodium cages, an octahedral cobalt MgO hole, and C20 fullerenes. Density functional the...

The most stable fullerene structures from C20 to C60 are chosen to study the energetics and geometrical consequences of encapsulating the rare gas elements He, Ne, or Ar inside the fullerene cage using dispersion corrected density functional theory. An exponential increase in stability is found with increasing number of carbon atoms. A similar exponential law is found for the volume expansion o...

A direct correlation between π- and spherical aromaticity of the aromatic structures was established by showing that they shared a characteristic shielding cone, resulting from a specific orientation of the applied field. Herein, we revealed the presence of a related long-range shielding cone in spherical aromatic species that was demonstrated through C20, C32, C50, and C60 Hirsh aromatic fulle...