First-principles study of the stability of graphene and adsorption of halogen atoms (F, Cl and Br) on hydrogen passivated graphene

First-principles calculations based on Hartree–Fock (HF) and density functional theory (DFT) levels of approximation have been carried out in order to study the stability of graphene clusters as a function of number of carbon atoms (N). The variation of calculated binding energy per carbon atom with corresponding number of carbon atoms (N) in graphene cluster almost saturates after the cluster size consisting of 96 carbon atoms, with binding energy per carbon atom 8.24 eV/atom. Adsorption of halogen atoms, ( F , Cl and Br ), on hydrogen passivated graphene ( H -graphene) was also studied systematically through first-principles DFT calculations by taking five different H -graphene clusters. The calculations showed that the most stable adsorption site for halogen adatoms on H -graphene being T site with binding energy 2.41 eV ( F ), 1.48 eV ( Cl ) and 1.19 eV ( Br ) on the H -graphene cluster consisting 96 carbon atoms. Moreover, on increasing the size of H -graphene cluster, the binding energy of halogen adatoms found to be increasing. The distances of adatom from the nearest carbon atom of H -graphene sheet were 1.47 Å ( F ), 2.71 Å ( Cl ) and 3.01 Å ( Br ), however, the adatom heights from the H -graphene basal plane were 2.22 Å ( F ), 2.90 Å ( Cl ), and 3.19 Å ( Br ). The bonding of halogen adatoms on H -graphene were through the charge transfer; 0.30 | e | ( F ), 0.37 | e | ( Cl ) and 0.19 | e | ( Br ), from H -graphene to adatoms and includes the negligible local distortion in the underlying planner H -graphene. Charge redistribution upon adsorption induces significant dipole moments 2.16 D ( F ), 4.81 D ( Cl ) and 3.08 D ( Br ) on H -graphene. The calculated HOMO–LUMO energy gap of adatom- H -graphene and H -graphene does not differ significantly up to the cluster size N = 30, however, beyond N = 30 adsorption of halogen adatoms significantly opens the HOMO–LUMO energy gap on H -graphene and the opening of HOMO–LUMO energy gap also saturates from N = 96. Correlation of computed HOMO–LUMO energy gap and corresponding binding energy of adatom- H -graphene systems have been also studied.

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The Hydrogen Passivated Graphene Cluster and its Stability - First Principle DFT (B3LYP) Levels of Approximation with the Basis Set 3-21G

Kathford Journal of Engineering and Management ◽

10.3126/kjem.v1i1.22013 ◽

2018 ◽

Vol 1 (1) ◽

pp. 5-10

Author(s):

Debendra Baniya

Keyword(s):

Binding Energy ◽

Carbon Atom ◽

State Energy ◽

Population Analysis ◽

Basis Set ◽

Mulliken Population ◽

B3lyp Level ◽

Reported Data ◽

Homo Lumo ◽

Graphene Cluster

First-principles DFT (B3LYP) levels of calculations with the basis set 3-21G have been carried out in order to study the geometric stability and electronic properties of hydrogen passivated graphene (H-graphene) clusters(CN) (where N = 6, 10, 13, 16, 22, 24, 27, 30, 35, 37, 40, 42, 45, 47, 48, 50, 52, 54, 70 and 96) and perform the DOS spectrum on H-graphene (C16H10, C24H12, C30H14, C48H18, C70H22 and C96H24) using Mulliken population analysis by the Gaussian 03 W set of programs. The variations of ground state energy of graphene clusters are observed on sizes and corresponding number of carbon atoms. The binding energy per carbon atom is the function of carbon atoms for the number of carbon atoms less than 30 and saturated at carbon’s number 30 and more in the DFT (B3LYP) levels of approximation with the basis set 3-21G. The binding energy per carbon atom of a pure graphene sheet C32 is 8.03 eV/atom in the DFT (B3LYP) level of approximation with the choice of the basis set 3-21G, which is acceptable with previous reported data 7.91 eV/atom. The HOMO-LUMO gap in NBO is studied for some H-grapheneclustors C16H10, C24H12, C30H14, C48H18, C70H22 and C96H24.

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A DFT Study of Geometric Structure and Stability of Iron-Silicon Clusters

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1048.369 ◽

2014 ◽

Vol 1048 ◽

pp. 369-372

Author(s):

Shuai Qin Yu ◽

Hong Nan Ye

Keyword(s):

Density Functional Theory ◽

Geometric Structure ◽

Density Functional ◽

Energy Gap ◽

Surface Site ◽

Silicon Clusters ◽

Lumo Energy ◽

Functional Theory ◽

The Stability ◽

Homo Lumo

Geometric structures of Fe6-xSix(x=1-5) clusters have been systematically studied at the BPW91 level by density-functional theory (DFT). Calculated results show that the Fe atoms of the lowest-energy structures of Fe6-xSix clusters tend to go together, and Si atoms tend to occupy surface site bonding with iron atoms as many as possible. Further, we analyze the stability of the lowest-energy structures of Fe6-xSix clusters, and the corresponding results of the HOMO, LUMO as well as the HOMO-LUMO energy gap show that the Fe5Si and Fe4Si2 clusters have special stability.

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A DFT Study of Vanadium Doped Gold Nanoalloy Clusters

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.777.183 ◽

2018 ◽

Vol 777 ◽

pp. 183-189 ◽

Cited By ~ 4

Author(s):

Prabhat Ranjan ◽

Tanmoy Chakraborty

Keyword(s):

Experimental Data ◽

Density Functional ◽

Energy Gap ◽

Linear Regression Analysis ◽

Gold Clusters ◽

Electrophilicity Index ◽

Lumo Energy ◽

Functional Theory ◽

The Stability ◽

Homo Lumo

The electronic and optical properties of AunV (n=1-8) nanoalloy clusters have been investigated invoking Density Functional Theory (DFT) based descriptors. Conceptual DFT based global descriptors have been used to exhibit experimental properties qualitatively. In this report, the experimental properties of AunV (n=1-8) nanoalloy clusters are correlated in terms of DFT based descriptors viz., HOMO-LUMO energy gap, Hardness, Softness, Electronegativity, Electrophilicity Index and Dipole Moment. The doping of single vanadium atom in gold clusters enhances the stability of gold clusters and also display pronounced odd-even oscillation behaviors. The computed bond length of instant clusters are numerically close with experimental data. The linear regression analysis has been done in terms of correlation between our computed descriptors and their experimental counterparts.

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A Computational Study of Catalytic Platinum Nanoparticles With and Without OH Chemisorption During Reactions

ASME 2008 3rd Energy Nanotechnology International Conference ◽

10.1115/enic2008-53029 ◽

2008 ◽

Author(s):

Mikhail Sekachev ◽

Cheng-Xian Lin ◽

Zhiyu Hu ◽

Don Dareing

Keyword(s):

Binding Energy ◽

Total Energy ◽

Platinum Nanoparticles ◽

Cluster Size ◽

Density Functional ◽

Energy Gap ◽

Computational Study ◽

Basis Set ◽

Functional Theory ◽

The Stability

In this paper, various energies and geometries of pure platinum nanoparticles and those of platinum nanoparticles with adsorbed OH were investigated. Ten different platinum clusters of up to 28 atoms were studied using spin-unrestricted density functional theory (DFT) with a double numerical plus polarization basis set. Three different shapes were presented, and the effect of cluster size on binding energy, total energy, and HOMO-LUMO energy gap was investigated. The same set of calculations was performed for selected clusters with OH adsorbate on the Pt(111) surface. The results show that the stability of both the pure clusters and the clusters with adsorbed OH molecule increases with an increase of cluster size. This fact indicates that direct influence of the size of Pt cluster on the reaction rate is possible, and the understanding of how cluster size would affect binding energy is important. The effect of cluster size on total energy of molecule was shown to be a linear function independent of cluster type, as expected. We also found that optimized (stable) Pt clusters were bigger in size than that of the initial clusters, or clusters with bulk geometry.

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A p–n fusion strategy to design bipolar organic materials for high-energy-density symmetric batteries

Journal of Materials Chemistry A ◽

10.1039/d1ta02059e ◽

2021 ◽

Author(s):

Jihyeon Kim ◽

Heechan Kim ◽

Sechan Lee ◽

Giyun Kwon ◽

Taewon Kang ◽

...

Keyword(s):

Energy Density ◽

Organic Material ◽

Energy Gap ◽

High Energy ◽

High Energy Density ◽

Lumo Energy ◽

Fusion Strategy ◽

Redox Active ◽

Bipolar Type ◽

Homo Lumo

A new bipolar-type redox-active organic material with a wide HOMO–LUMO energy gap is designed though the ‘p–n fusion’ strategy.

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STRUCTURES, ABSORPTION SPECTRA, AND ELECTRONIC PROPERTIES OF POLYFLUORENE AND ITS DERIVATIVES: A THEORETICAL STUDY

Journal of Theoretical and Computational Chemistry ◽

10.1142/s0219633606002520 ◽

2006 ◽

Vol 05 (03) ◽

pp. 595-608 ◽

Cited By ~ 13

Author(s):

KRIENGSAK SRIWICHITKAMOL ◽

SONGWUT SURAMITR ◽

POTJAMAN POOLMEE ◽

SUPA HANNONGBUA

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Energy Gap ◽

Level Energy ◽

Excitation Energies ◽

Lumo Energy ◽

Functional Theory ◽

Local Energy Minimum ◽

Pi Systems ◽

Homo Lumo

The structural and energetic properties of polyfluorene and its derivatives were investigated, using quantum chemical calculations. Conformational analysis of bifluorene was performed by using ab initio (HF/6-31G* and MP2/6-31G*) and density functional theory (B3LYP/6-31G*) calculations. The results showed that the local energy minimum of bifluorene lies between the coplanar and perpendicular conformation, and the B3LYP/6-31G* calculations led to the overestimation of the stability of the planar pi systems. The HOMO-LUMO energy differences of fluorene oligomers and its derivatives — 9,9-dihexylfluorene (DHPF), 9,9-dioctylfluorene (PFO), and bis(2-ethylhexyl)fluorene (BEHPF) — were calculated at the B3LYP/6-31G* level. Energy gaps and effective conjugation lengths of the corresponding polymers were obtained by extrapolating HOMO-LUMO energy differences and the lowest excitation energies to infinite chain length. The lowest excitation energies and the maximum absorption wavelength of polyfluorene were also performed, employing the time-dependent density functional theory (TDDFT) and ZINDO methods. The extrapolations, based on TDDFT and ZINDO calculations, agree well with experimental results. These theoretical methods can be useful for the design of new polymeric structures with a reducing energy gap.

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5-Methyl-1,3-phenylene bis[5-(dimethylamino)naphthalene-1-sulfonate]: crystal structure and DFT calculations

Acta Crystallographica Section E Crystallographic Communications ◽

10.1107/s2056989019009058 ◽

2019 ◽

Vol 75 (7) ◽

pp. 1079-1083

Author(s):

Tanwawan Duangthongyou ◽

Ramida Rattanakam ◽

Kittipong Chainok ◽

Songwut Suramitr ◽

Thawatchai Tuntulani ◽

...

Keyword(s):

Dft Calculations ◽

Energy Gap ◽

Rotation Axis ◽

Three Dimensional ◽

Hydrogen Atoms ◽

Lumo Energy ◽

Compound C ◽

Dansyl Group ◽

Weak Hydrogen Bonds ◽

Homo Lumo

The title compound, C31H30N2S2O6, possesses crystallographically imposed twofold symmetry with the two C atoms of the central benzene ring and the C atom of its methyl substituent lying on the twofold rotation axis. The two dansyl groups are twisted away from the plane of methylphenyl bridging unit in opposite directions. The three-dimensional arrangement in the crystal is mainly stabilized by weak hydrogen bonds between the sulfonyl oxygen atoms and the hydrogen atoms from the N-methyl groups. Stacking of the dansyl group is not observed. From the DFT calculations, the HOMO–LUMO energy gap was found to be 2.99 eV and indicates n→π* and π→π* transitions within the molecule.

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FIRST-PRINCIPLES STUDY OF STRUCTURES AND ELECTRONIC PROPERTIES FOR NITRIDE-DOPED ALUMINUM CLUSTERS

International Journal of Modern Physics B ◽

10.1142/s0217979205031018 ◽

2005 ◽

Vol 19 (15n17) ◽

pp. 2380-2385 ◽

Cited By ~ 3

Author(s):

BAOLIN WANG ◽

DALING SHI ◽

XIAOSHUANG CHEN ◽

GUANGHOU WANG ◽

JIJUN ZHAO

Keyword(s):

Genetic Algorithm ◽

Electronic Properties ◽

Atomic Structure ◽

Ground State ◽

First Principles ◽

Cluster Size ◽

Aluminum Clusters ◽

Structural And Electronic Properties ◽

Ground State Structures ◽

Homo Lumo

By using Gaussian98 package at BPW91 6-31g(d,p) level combined a genetic algorithm (GA) simulation, we have studied the lowest energy structural and electronic properties of the Al n N ( n =2-13) clusters. The ground-state structures, the charge transfers from Al to N site, HOMO-LUMO gap and the covalent, ionic and metallic nature with cluster size and atomic structure are investigated. Al 7 N , Al 9 N and Al 12 N cluster is found particularly stable among the Al n N clusters.

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SOLVENT EFFECTS ON THE ELECTRONIC STRUCTURE AND NON-LINEAR OPTICAL PROPERTIES OF PYRENE AND SOME OF ITS DERIVATIVES BASED ON DENSITY FUNCTIONAL THEORY

FUDMA Journal of Sciences ◽

10.33003/fjs-2020-0404-477 ◽

2021 ◽

Vol 4 (4) ◽

pp. 236-251

Author(s):

A. S. Gidado ◽

L. S. Taura ◽

A. Musa

Keyword(s):

Density Functional Theory ◽

Gas Phase ◽

Density Functional ◽

Energy Gap ◽

Chemical Reactivity ◽

Basis Set ◽

Lumo Energy ◽

Functional Theory ◽

Organic Optoelectronic ◽

Homo Lumo

Pyrene (C16H10) is an organic semiconductor which has wide applications in the field of organic electronics suitable for the development of organic light emitting diodes (OLED) and organic photovoltaic cells (OPV). In this work, Density Functional Theory (DFT) using Becke’s three and Lee Yang Parr (B3LYP) functional with basis set 6-311++G(d, p) implemented in Gaussian 03 package was used to compute total energy, bond parameters, HOMO-LUMO energy gap, electron affinity, ionization potential, chemical reactivity descriptors, dipole moment, isotropic polarizability (α), anisotropy of polarizability ( Δ∝) total first order hyper-polarizability () and second order hyperpolarizability (). The molecules used are pyrene, 1-chloropyrene and 4-chloropyrene in gas phase and in five different solvents: benzene, chloroform, acetone, DMSO and water. The results obtained show that solvents and chlorination actually influenced the properties of the molecules. The isolated pyrene in acetone has the largest value of HOMO-LUMO energy gap of and is a bit closer to a previously reported experimental value of and hence is the most stable. Thus, the pyrene molecule has more kinetic stability and can be described as low reactive molecule. The calculated dipole moments are in the order of 4-chloropyrene (1.7645 D) < 1-chloropyrene (1.9663 D) in gas phase. The anisotropy of polarizability ( for pyrene and its derivatives were found to increase with increasing polarity of the solvents. In a nutshell, the molecules will be promising for organic optoelectronic devices based on their computed properties as reported by this work.

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