ELECTRONIC PROPERTIES OF HETEROFULLERENES C59X (X=Si, O AND Be)

2000 ◽  
Vol 14 (01) ◽  
pp. 23-29 ◽  
Author(s):  
JING LU ◽  
XINWEI ZHANG ◽  
XIANGENG ZHAO
Keyword(s):  
Electronic Properties ◽  
Molecular Orbital ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Local Density ◽  
Electron Affinities ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital ◽  
Local Density Functional ◽  
Silicon Oxygen

It has been found in earlier calculations that by replacing one C atom with one N atom, one electron is doped in the lowest unoccupied molecular orbital (LUMO) of C60 while by replacing with one B atom, one hole is doped in the highest occupied molecular orbital (HOMO) of C60. In this paper, we have performed discrete-variational local density functional calculations on single silicon, oxygen and beryllium-substituted heterofullerenes. No carrier is doped in the C60-derived orbitals upon Si substitution except for the reduced LUMO–HOMO gap. Two electrons are doped in the LUMO of C60 upon O substitution and instead, two holes are doped in the HOMO of C60 upon Be substitution. Ionization potentials and electron affinities can be altered dramatically by substitution and in general, C60 becomes more reactive upon substitution.

Electronic and geometric structure of AuxCuy clusters studied by density functional theory

2014 ◽  
Vol 25 (06) ◽  
pp. 1450011 ◽  
Author(s):  
Y. Kadioglu ◽  
O. Üzengi Aktürk ◽  
M. Tomak
Keyword(s):  
Density Functional Theory ◽  
Molecular Orbital ◽  
Density Functional ◽  
Local Density ◽  
Three Dimensional ◽  
Binding Energies ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital

We have determined the stable structures of Au Cu n, Au 2 Cu n, Au 3 Cu n and Au x Cu 8-x clusters. It has been observed that Au Cu n, Au 2 Cu n and Au 3 Cu n systems have two-dimensional (2D) structures up to six atoms and they become three-dimensional (3D) afterwards. Au x Cu 8-x clusters favor 3D structures till the Au 7 Cu 1 cluster. We have found a lowest energy isomer of Au 6 Cu 2 from the literature. Bond lengths, binding energies, density of states (DOS), highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO-LUMO) gaps, ionization potential (IP) and electron affinity (EA) have been calculated for these structures using the first principles density functional theory (DFT) within the generalized gradient approximation (GGA) and the local density approximation (LDA). Generally, we have observed the overlap between s electrons of Cu and p electrons of Au near the Fermi level. Charge transfers are calculated by using the Löwdin analysis. It is observed that one Cu atom does not significantly modify the clusters which have more gold atoms. It is also seen that these clusters generally have nonmagnetic properties and results are consistent with the hybridization between s and d orbitals of Au in Au x Cu 8-x clusters.

DFTB Calculation of Si Atomic Chains’ Structures and Electronic Properties

2016 ◽  
Vol 848 ◽  
pp. 494-497
Author(s):  
Xiu Min Xu ◽  
Li Jun Wu ◽  
Lin Zhang
Keyword(s):  
Electronic Properties ◽  
Molecular Orbital ◽  
Density Functional ◽  
Energy Gap ◽  
Tight Binding ◽  
Functional Theory ◽  
Symmetrical Distribution ◽  
Highest Occupied Molecular Orbital ◽  
Atomic Chains ◽  
Lowest Unoccupied Molecular Orbital

In this paper, structures and electronic properties of atomic chains with 5 to 20 silicon atoms and different atomic distances (d = 1.652 ~ 2.752Å) were calculated by the tight-binding method based on density functional theory. The results showed that the majority of the silicon atomic chains were symmetrical structures. When the number of silicon atoms was small, the silicon atomic chains were linear, when the silicon atomic chains had seven or more silicon atoms zigzag structures appeared. With the increase of the distance between atoms, atomic chains were gathering. When the number of silicon atoms was between 10 and 20, the charges on the silicon atoms appeared as a symmetrical distribution. With the increase of the number of atoms, the energy of silicon atomic chains decreased gradually. As the distance between atoms and atomic number changed, HOMO (highest occupied molecular orbital electrons) -LUMO (lowest unoccupied molecular orbital electrons) energy gap changed as well.

ELECTRONIC STRUCTURES OF ENDOHEDRAL Sr@C60, Ba@C60, Fe@C60 and Mn@C60

1999 ◽  
Vol 13 (03n04) ◽  
pp. 97-101 ◽  
Author(s):  
JING LU ◽  
LIXIN GE ◽  
XINWEI ZHANG ◽  
XIANGENG ZHAO
Keyword(s):  
Electronic Structures ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Local Density ◽  
Ionization Potentials ◽  
Electron Affinities ◽  
Oxidation Number ◽  
Endohedral Fullerenes ◽  
Valence Electrons ◽  
Local Density Functional

Discrete-variational local density functional calculations on endoheral Sr @ C 60, Ba @ C 60, Fe @ C 60 and Mn @ C 60 are performed. The Sr (5s2) and Ba (6s2) atoms denote their two s valence electrons to the C 60 cage, described as [Formula: see text] and [Formula: see text]. The Fe (3d64s2) and Mn (3d54s2) atom are in only +1 valence, rather small oxidation number. The electron affinities and ionization potentials of the four endohedral fullerenes are given.

scholarly journals Geometry, Energy, and Some Electronic Properties of Carbon Polyprismanes: Ab Initio and Tight-Binding Study

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Konstantin P. Katin ◽  
Stanislav A. Shostachenko ◽  
Alina I. Avkhadieva ◽  
Mikhail M. Maslov
Keyword(s):  
Electronic Properties ◽  
Molecular Orbital ◽  
Density Functional ◽  
Tight Binding ◽  
Binding Energies ◽  
Effective Length ◽  
Binding Model ◽  
Highest Occupied Molecular Orbital ◽  
Semiconducting Properties ◽  
Lowest Unoccupied Molecular Orbital

We report geometry, energy, and some electronic properties of [n,4]- and [n,5]prismanes (polyprismanes): a special type of carbon nanotubes constructed from dehydrogenated cycloalkane C4- and C5-rings, respectively. Binding energies, interatomic bonds, and the energy gaps between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) have been calculated using density functional approach and nonorthogonal tight-binding model for the systems up to thirty layers. It is found that polyprismanes become more thermodynamically stable as their effective length increases. Moreover, they may possess semiconducting properties in the bulk limit.

Geometrical and electronic properties of PdWSin (n=10–20) semiconductor materials

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Rui Chen ◽  
Fan Lin ◽  
Hua Jin ◽  
Run-Ning Zhao
Keyword(s):  
Electronic Properties ◽  
Molecular Orbital ◽  
Density Functional ◽  
Silicon Clusters ◽  
Functional Methods ◽  
Highest Occupied Molecular Orbital ◽  
Doped Silicon ◽  
Lowest Unoccupied Molecular Orbital ◽  
Silicon Frame ◽  
Homo Lumo

Abstract Geometries and electronic properties of PdWSin (n=10–20) clusters are investigated by density functional methods. According to our calculated results, it is obvious that tungsten (W)-encapsulated silicon frame determines the final PdWSin (n=10–20) forms because W and silicon (Si) interactions are stronger than palladium (Pd)-Si interactions. The electronic charges are transferred from the Si frame to W firstly and Pd finally, which is completely different from the homoatomic transition metal (TM)2-doped silicon clusters. The calculated highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gaps exhibit that PdWSi12 has the biggest HOMO-LUMO gap.

scholarly journals Electronic Properties of Triangle Molybdenum Disulfide (MoS2) Clusters with Different Sizes and Edges

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1157
Author(s):  
Songsong Wang ◽  
Changliang Han ◽  
Liuqi Ye ◽  
Guiling Zhang ◽  
Yangyang Hu ◽  
...  
Keyword(s):  
Quantum Chemistry ◽  
Electronic Properties ◽  
Absorption Spectra ◽  
Molecular Orbital ◽  
Electronic Structures ◽  
Edge States ◽  
Frontier Orbitals ◽  
Edge Structure ◽  
Highest Occupied Molecular Orbital ◽  
Lowest Unoccupied Molecular Orbital

The electronic structures and transition properties of three types of triangle MoS2 clusters, A (Mo edge passivated with two S atoms), B (Mo edge passivated with one S atom), and C (S edge) have been explored using quantum chemistry methods. The highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) gap of B and C is larger than that of A, due to the absence of the dangling of edge S atoms. The frontier orbitals (FMOs) of A can be divided into two categories, edge states from S3p at the edge and hybrid states of Mo4d and S3p covering the whole cluster. Due to edge/corner states appearing in the FMOs of triangle MoS2 clusters, their absorption spectra show unique characteristics along with the edge structure and size.

scholarly journals Computational Aspects of (E)-O-Carbomethoxy Methyl Oxime Ether of 1,3-Dimethyl-2,6-Diphenylpiperidin-4-One

2019 ◽  
Vol 9 (2S2) ◽  
pp. 701-706
Keyword(s):  
Molecular Orbital ◽  
Density Functional ◽  
Atomic Charge ◽  
Molecular Geometry ◽  
Biologically Active ◽  
Oxime Ether ◽  
Structure And Property ◽  
Highest Occupied Molecular Orbital ◽  
Computational Aspects ◽  
Lowest Unoccupied Molecular Orbital

Density Functional Theoretical (DFT) studies on the biologically active oxime ether derived from 1,3-dimethyl-2,6-diphenylpiperidin-4-one has been carried out. Various quantum chemical parameters of the molecule viz. molecular geometry, Highest Occupied Molecular Orbital – Lowest Unoccupied Molecular Orbital (HOMO–LUMO) energies, Non-Linear Optical (NLO) properties, Mulliken atomic charge distribution were obtained theoretically and compared with the single crystal data. An insight into the structure and property correlation revealed the probable behavior of the molecule studied

Computational and Experimental Study onthe Adsorption and Inhibition Effects of 1,3-Benzothiazol-6-ol on the Corrosion ofSteel X80 in Acidic Solution

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Iman Danaee ◽  
Paria Nikparsa ◽  
Mohammad Reza Khosravi-Nikou
Keyword(s):  
Molecular Orbital ◽  
Density Functional ◽  
Acidic Solution ◽  
Energy Gap ◽  
Force Microscopy ◽  
Highest Occupied Molecular Orbital ◽  
Low Concentrations ◽  
Noise Data ◽  
Chemical Factors ◽  
Lowest Unoccupied Molecular Orbital

Abstract In this work, the adsorption and inhibition behavior of 1,3-benzothiazol-6-ol were investigated by computational and experimental techniques for steel X80 corrosion in acidic solution. The density functional theory was carried out and quantum chemical factors like the energy gap, energy of highest occupied molecular orbital, the energy of lowest unoccupied molecular orbital, the fraction of electron transferred, and Mulliken charges have been calculated. In addition, according to quantum calculation, S atom in 1,3-benzothiazol-6-ol indicated more tendency for electrophilic attack in adsorption. The main reason for high inhibition efficiencies in very low concentrations is the planar and simplicity of inhibitor structure which leads to increasing the efficiency of adsorption by functional group especially sulfur. Electrochemical frequency modulation and potentiodynamic polarization indicated that this material has excellent inhibiting features in very low concentrations. The influence of DC trend on the explanation of electrochemical noise data was evaluated by polynomial fitting and the optimum polynomial order m = 5 was obtained. Noise resistance and the inhibition efficiency was calculated and compared in different methods. The theory of shot noise in frequency domain was used to obtain the electrochemical event charge. The corroded surface of steel in the absence and existence of thiazole compound was studied by Atomic force microscopy.

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