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Artykuły w czasopismach na temat „Density Functional Theory (DFT) - First Principles Calculations”

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Data publikacji: 7 września 2023

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1

Wang, Yuqiu, Binkai Yu, Jin Xiao, Limin Zhou i Mingzhe Chen. "Application of First Principles Computations Based on Density Functional Theory (DFT) in Cathode Materials of Sodium-Ion Batteries". Batteries 9, nr 2 (27.01.2023): 86. http://dx.doi.org/10.3390/batteries9020086.

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Sodium-ion batteries (SIBs) have been widely explored by researchers because of their abundant raw materials, uniform distribution, high-energy density and conductivity, low cost, and high safety. In recent years, theoretical calculations and experimental studies on SIBs have been increasing, and the applications and results of first-principles calculations have aroused extensive interests worldwide. Herein, the authors review the applications of density functional (DFT) theory in cathode materials for SIBs, summarize the applications of DFT in transition-metal oxides/chalcogenides, polyanionic compounds, Prussian blue, and organic cathode materials for SIBs from three aspects: diffusion energy barrier and diffusion path, energy calculation and structure, and electronic structure. The relationship between the structure and performance of the battery material will be comprehensively understood by analyzing the specific working principle of battery material through theoretical calculation and combining with high-precision experimental characterization technologies. Selecting materials with good performance from a large number of electrode materials through theoretical calculation can avoid unnecessary complex experiments and instrument characterizations. With the gradual deepening of research, the DFT calculation will play a greater role in the sodium-ion battery electrode field.

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Hashir, P., P. P. Pradyumnan, Aadil Fayaz Wani i Kulwinder Kaur. "Experimental and First-Principles Thermoelectric studies of Bulk ZnO". IOP Conference Series: Materials Science and Engineering 1263, nr 1 (1.10.2022): 012025. http://dx.doi.org/10.1088/1757-899x/1263/1/012025.

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The Thermoelectric perspective to produce electricity from waste heat has obtained great attention over the last few years. However, the fulfillment of energy requirement of the contemporary world by the thermoelectric method can be achieved by developing good thermoelectric materials of high conversion efficiency. Density functional theory (DFT) is widely used simulation technique in the materials science field for computing electronic properties of the materials. In our DFT calculation Quantum Espresso (QE) package were used to investigate the electronic band structure as well as electronic density of states of bulk ZnO sample. To express core electrons, projector-augmented wave (PAW) pseudopotentials were chosen and to optimize band structure LDA+U method of DFT approximation was opted. Our DFT calculations give direct band gap 3.2004 eV and the experimental value is 3.24 eV. Our works are found to be good acceptance with previously reported values and the DFT study via QE and BoltzTraP codes are suitable for predicting the thermoelectric properties of semiconductor materials.

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Ali, Abdelnabi. "Electronic and magnetic proprieties of NiO surfaces from first-principles". FES Journal of Engineering Sciences 11, nr 1 (18.01.2022): 37–42. http://dx.doi.org/10.52981/fjes.v11i1.1732.

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Density functional theory (DFT) is used to study the electronic and magnetic properties of different surfaces of NiO. The electronic and magnetic properties of forming different surfaces of Nicoles such as (001), (110), (101), and (111) were studied using density functional theory calculations from the first principle used. Our result found that the band gap changed dramatically, and the spin projected density of state changed the dominations of the majority and minority of spin channels around the Fermi level, and the charge density of the bulk and NiO (111) surface is also discussed. However, the magnetic properties observed the increasing and decreasing spin magnetic moments and found significant magnetic moments for O atoms in the NiO (101) slab. These features lead to a surprisingly diverse set of different surface electronic structures. The study observed that DFT + U density functional theory might be a valuable method for high-throughput workflows that require reliable band gap predictions at a moderate computational cost.

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4

Sarmadian, Nasrin, Rolando Saniz, Bart Partoens, Dirk Lamoen, Kalpana Volety, Guido Huyberechts i Johan Paul. "High throughput first-principles calculations of bixbyite oxides for TCO applications". Phys. Chem. Chem. Phys. 16, nr 33 (2014): 17724–33. http://dx.doi.org/10.1039/c4cp02788d.

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We present a high-throughput computing scheme based on density functional theory (DFT) to generate a class of oxides and screen them with the aim of identifying those that might be electronically appropriate for transparent conducting oxide (TCO) applications.

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5

Xia, Lu, Thomas Tybell i Sverre M. Selbach. "Bi vacancy formation in BiFeO3 epitaxial thin films under compressive (001)-strain from first principles". Journal of Materials Chemistry C 7, nr 16 (2019): 4870–78. http://dx.doi.org/10.1039/c8tc06608f.

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6

Teng, Tsung-Fan, Santhanamoorthi Nachimuthu, Wei-Hsiu Hung i Jyh-Chiang Jiang. "A first principles study of H2S adsorption and decomposition on a Ge(100) surface". RSC Advances 5, nr 5 (2015): 3825–32. http://dx.doi.org/10.1039/c4ra08887e.

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7

Usseinov, Abay, Zhanymgul Koishybayeva, Alexander Platonenko, Vladimir Pankratov, Yana Suchikova, Abdirash Akilbekov, Maxim Zdorovets, Juris Purans i Anatoli I. Popov. "Vacancy Defects in Ga2O3: First-Principles Calculations of Electronic Structure". Materials 14, nr 23 (2.12.2021): 7384. http://dx.doi.org/10.3390/ma14237384.

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First-principles density functional theory (DFT) is employed to study the electronic structure of oxygen and gallium vacancies in monoclinic bulk β-Ga2O3 crystals. Hybrid exchange–correlation functional B3LYP within the density functional theory and supercell approach were successfully used to simulate isolated point defects in β-Ga2O3. Based on the results of our calculations, we predict that an oxygen vacancy in β-Ga2O3 is a deep donor defect which cannot be an effective source of electrons and, thus, is not responsible for n-type conductivity in β-Ga2O3. On the other hand, all types of charge states of gallium vacancies are sufficiently deep acceptors with transition levels more than 1.5 eV above the valence band of the crystal. Due to high formation energy of above 10 eV, they cannot be considered as a source of p-type conductivity in β-Ga2O3.

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8

Muhammad, Rafique, Yong Shuai i He-Ping Tan. "A first-principles study on alkaline earth metal atom substituted monolayer boron nitride (BN)". Journal of Materials Chemistry C 5, nr 32 (2017): 8112–27. http://dx.doi.org/10.1039/c7tc02894f.

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This paper presents first-principles density functional theory (DFT) calculations for the structural, electronic, magnetic and optical properties of monolayer boron nitride (BN) doped with different alkaline earth metal (AEM) atoms.

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9

Pulido, Ruth, Nelson Naveas, Raúl J. Martin-Palma, Fernando Agulló-Rueda, Victor R. Ferró, Jacobo Hernández-Montelongo, Gonzalo Recio-Sánchez, Ivan Brito i Miguel Manso-Silván. "Phonon Structure, Infra-Red and Raman Spectra of Li2MnO3 by First-Principles Calculations". Materials 15, nr 18 (8.09.2022): 6237. http://dx.doi.org/10.3390/ma15186237.

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The layer-structured monoclinic Li2MnO3 is a key material, mainly due to its role in Li-ion batteries and as a precursor for adsorbent used in lithium recovery from aqueous solutions. In the present work, we used first-principles calculations based on density functional theory (DFT) to study the crystal structure, optical phonon frequencies, infra-red (IR), and Raman active modes and compared the results with experimental data. First, Li2MnO3 powder was synthesized by the hydrothermal method and successively characterized by XRD, TEM, FTIR, and Raman spectroscopy. Secondly, by using Local Density Approximation (LDA), we carried out a DFT study of the crystal structure and electronic properties of Li2MnO3. Finally, we calculated the vibrational properties using Density Functional Perturbation Theory (DFPT). Our results show that simulated IR and Raman spectra agree well with the observed phonon structure. Additionally, the IR and Raman theoretical spectra show similar features compared to the experimental ones. This research is useful in investigations involving the physicochemical characterization of Li2MnO3 material.

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10

Gawai, U. P., U. P. Deshpande i B. N. Dole. "A study on the synthesis, longitudinal optical phonon–plasmon coupling and electronic structure of Al doped ZnS nanorods". RSC Advances 7, nr 20 (2017): 12382–90. http://dx.doi.org/10.1039/c6ra28180j.

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11

Dzade, N. Y., A. Roldan i N. H. de Leeuw. "Surface and shape modification of mackinawite (FeS) nanocrystals by cysteine adsorption: a first-principles DFT-D2 study". Physical Chemistry Chemical Physics 18, nr 47 (2016): 32007–20. http://dx.doi.org/10.1039/c6cp05913a.

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The surface and shape modulation of mackinawite (FeS) nanoparticles by amino acid cysteine adsorption is investigated using a first-principles density functional theory calculations, corrected for dispersion-interactions (DFT-D2).

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12

Ullah, Saif, Akhtar Hussain i Fernando Sato. "Rectangular and hexagonal doping of graphene with B, N, and O: a DFT study". RSC Advances 7, nr 26 (2017): 16064–68. http://dx.doi.org/10.1039/c6ra28837e.

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13

Nayeb Sadeghi, Safoura, Mona Zebarjadi i Keivan Esfarjani. "Non-linear enhancement of thermoelectric performance of a TiSe2 monolayer due to tensile strain, from first-principles calculations". Journal of Materials Chemistry C 7, nr 24 (2019): 7308–17. http://dx.doi.org/10.1039/c9tc00183b.

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Using first-principles density functional theory (DFT) calculations combined with the Boltzmann transport theory, we investigate the effect of strain on the electronic and thermoelectric transport properties of the 1T-TiSe₂ monolayer, a two-dimensional (2D) material, and compare it with the bulk phase within the PBE, LDA+U and HSE exchange–correlation functionals.

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14

Guo, Feng, Hong Zhang, Chao-Yang Zhang, Xin-Lu Cheng i Hai-Quan Hu. "Effect of electronic excitation to intermolecular proton transfer in bulk nitromethane: Tuned parameter SCC-DFTB and first principles study". Journal of Theoretical and Computational Chemistry 14, nr 02 (marzec 2015): 1550013. http://dx.doi.org/10.1142/s0219633615500133.

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To understand the reaction mechanism involving hydrogen transfers through hydrogen-bond bridge, we carried out both Self-Consistent Charge Density Functional Tight-Binding (SCC-DFTB) calculations of bulk nitromethane and Density Functional Theory (DFT) calculations of singlet ground state/triplet excited state molecular nitromethane using B3LYP functional. Firstly, we tuned the repulsive parameters of the SCC-DFTB method for nitromethane with dataset calculated from DFT at B3LYP/6-311g level. The molecular dynamics simulations are carried out with tuned parameters to get the dynamical properties of the bulk nitromethane, and the static calculations are intended to give energy profile of the reaction process. These calculations indicate the excitation of nitromethane molecule making the proton transfer reactions possible, and lowering the reaction barrier.

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15

Landa, Alexander, Per Söderlind i Amanda Wu. "Phase Stability in U-6Nb Alloy Doped with Ti from the First Principles Theory". Applied Sciences 10, nr 10 (15.05.2020): 3417. http://dx.doi.org/10.3390/app10103417.

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First-principles calculations within the density-functional-theory (DFT) approach are conducted in order to explore and explain the effect of small amounts of titanium on phase stability in the U-6Nb alloy. During rapid quenching from high to room temperature, metastable phases α′ (orthorhombic), α″ (monoclinic), and γ0 (tetragonal) can form, depending on Nb concentration. Important mechanical properties depend on the crystal structure and, therefore, an understanding of the effect of impurities on phase stability is essential. Insights on this issue are obtained from quantum-mechanical DFT calculations. The DFT framework does not rely on any material-specific assumptions and is therefore ideal for an unbiased investigation of the U-Nb system.

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16

Saleev, Vladimir, i Alexandra Shipilova. "First-principles calculations of LiNbO3 optical properties: From far-infrared to ultraviolet". Modern Physics Letters B 32, nr 05 (20.02.2018): 1850063. http://dx.doi.org/10.1142/s021798491850063x.

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We perform first-principles calculations of optical properties for ferroelectric phase of LiNbO3 crystal using density functional theory (DFT) for wide range of wavelengths, from far-infrared (IR) to ultraviolet. We study frequency dependence of complex dielectric tensor and related quantities, such as refractive and reflection indices, absorption coefficients, etc. Our calculation incorporates advantages of numerical approaches based on atomic-orbital all-electron Gaussian-type basis sets, as it is realized in CRYSTAL14 program. We compared predictions obtained in general-gradient approach with PBESOL exchange-correlation functional and in hybrid approach with PBESOL0 functional, and we have found that hybrid PBESOL0 functional is more applicable to describe the wide set of the experimental data.

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17

Jauris, I. M., C. F. Matos, C. Saucier, E. C. Lima, A. J. G. Zarbin, S. B. Fagan, F. M. Machado i I. Zanella. "Adsorption of sodium diclofenac on graphene: a combined experimental and theoretical study". Physical Chemistry Chemical Physics 18, nr 3 (2016): 1526–36. http://dx.doi.org/10.1039/c5cp05940b.

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The interactions of sodium diclofenac drug (s-DCF) with different graphene species were investigated using both first principles calculations based on Density Functional Theory (DFT) and adsorption experiments.

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18

Benco, Ľubomír, Thomas Demuth i François Hutschka. "Catalyic conversion of hydrocarbons in zeolites from first principles". Pure and Applied Chemistry 74, nr 11 (1.01.2002): 2097–100. http://dx.doi.org/10.1351/pac200274112097.

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The application of the density functional techniques to processes of the conversion of hydrocarbons in zeolites has been reviewed. The conversion of hydrocarbons over zeolites is an important industrial process. The microscopic steps of the conversion, however, are still not satisfactorily understood. In order to examine reaction pathways, both static and molecular dynamics density functional theory (DFT) calculations have been performed. Simulated structural and spectral properties compare reasonably with experimental data. Comparison of energies of physisorption and chemisorption indicates possible reaction channel of the conversion through the chemisorption at the specific O-sites of the zeolite.

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19

Gillan, M. J., P. J. D. Lindan, L. N. Kantorovich i S. P. Bates. "Molecular processes on oxide surfaces studied by first-principles calculations". Mineralogical Magazine 62, nr 5 (październik 1998): 669–85. http://dx.doi.org/10.1180/002646198548052.

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AbstractFirst-principles quantum techniques based on density functional theory (DFT) have made important contributions to the understanding of oxide surfaces over the last four years. Important features of these calculations include: the use of periodic boundary conditions, which avoid the edge effects associated with the cluster approach; plane-wave basis sets, which make the calculation of ionic forces straightforward, so that both static relaxation and dynamical simulation can be done; and the approximate inclusion of electron correlation. A short introduction to DFT techniques is given, and recent work on the structure and energetics of a variety of oxide surfaces is presented. It is shown how the techniques can be used to study molecular and dissociative adsorption of molecules on oxide surfaces, with the emphasis on water and simple organic molecules. The growing importance of dynamical first-principles simulation in the study of surface chemical reactions is illustrated.

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20

Hussain, Akhtar, Saif Ullah i M. Arshad Farhan. "Fine tuning the band-gap of graphene by atomic and molecular doping: a density functional theory study". RSC Advances 6, nr 61 (2016): 55990–6003. http://dx.doi.org/10.1039/c6ra04782c.

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First-principles density functional theory (DFT) based calculations were carried out to investigate the structural and electronic properties of beryllium and nitrogen co-doped and BeN/BeO molecules-doped graphene systems.

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21

Bouheddadj, Amina, Tarik Ouahrani, Wilfried G. Kanhounnon, Boufatah M. Reda, Sumeya Bedrane, Michael Badawi i Ángel Morales-García. "Low-dimensional HfS₂ as SO₂ adsorbent and gas sensor: effect of water and sulfur vacancies". Physical Chemistry Chemical Physics 23, nr 41 (2021): 23655–66. http://dx.doi.org/10.1039/d1cp04069c.

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First-principles based on density functional theory (DFT) calculations were performed to investigate the interaction of two-dimensional (2D) HfS2 with SO2, a harmful gas with implications for climate change.

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22

Bouheddadj, Amina, Tarik Ouahrani, Wilfried G. Kanhounnon, Boufatah M. Reda, Sumeya Bedrane, Michael Badawi i Ángel Morales-García. "Low-dimensional HfS₂ as SO₂ adsorbent and gas sensor: effect of water and sulfur vacancies". Physical Chemistry Chemical Physics 23, nr 41 (2021): 23655–66. http://dx.doi.org/10.1039/d1cp04069c.

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First-principles based on density functional theory (DFT) calculations were performed to investigate the interaction of two-dimensional (2D) HfS2 with SO2, a harmful gas with implications for climate change.

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23

Ullah, Saif, Akhtar Hussain, WaqarAdil Syed, Muhammad Adnan Saqlain, Idrees Ahmad, Ortwin Leenaerts i Altaf Karim. "Band-gap tuning of graphene by Be doping and Be, B co-doping: a DFT study". RSC Advances 5, nr 69 (2015): 55762–73. http://dx.doi.org/10.1039/c5ra08061d.

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First-principles density functional theory (DFT) calculations were carried out to investigate the structural and electronic properties of beryllium (Be) doped and, Be with boron (B) co-doped graphene systems.

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24

Lamichhane, S., N. Pantha i NP Adhikari. "Hydrogen storage on platinum decorated graphene: A first-principles study". BIBECHANA 11 (10.05.2014): 113–22. http://dx.doi.org/10.3126/bibechana.v11i0.10389.

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Adsorption of gaseous/molecular hydrogen on platinum (Pt) decorated and pristine graphene have been studied systematically by using density functional theory (DFT) level of calculations implemented by Quantum ESPRESSO codes. The Perdew-Burke-Ernzerhof (PBE) type generalized gradient approximation (GGA) exchange-correlation functional and London dispersion forces have been incorporated in the DFT-D2 level of algorithm for short and long range electron-electron interactions, respectively. With reference to the binding energy of Pt on different symmetry sites of graphene supercells, the bridge (B) site has been predicted as the best adsorption site. In case of 3×3 supercell of graphene (used for detail calculations), the binding energy has been estimated as 2.02 eV. The band structure and density of states calculations of Pt adatom graphene predict changes in electronic/magnetic properties caused by the atom (Pt). The adatom (Pt) also enhances the binding energy per hydrogen molecule in Pt-graphene comparing to that in pristine graphene and records the values within the range of 1.84 eV to 0.13 eV for one to eight molecules, respectively. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10389 BIBECHANA 11(1) (2014) 113-122

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25

Tang, Xiong, Lan Fang Yao, Xin Pei Yan i Jun Long Kang. "First-Principles Calculations on Pure and Y-Doped Anatase TiO₂". Key Engineering Materials 562-565 (lipiec 2013): 1166–70. http://dx.doi.org/10.4028/www.scientific.net/kem.562-565.1166.

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Using the First principles calculations, the crystal structure, band gap, total and partial density of states (DOS) of anatase TiO2and anatase TiO2doped with Yttrium were calculated by a plane-wave pseudopotential (PWPP) method based on density functional theory (DFT). The generalized gradient approximation (GGA) based on exchange-correlation energy optimization was employed to calculate them. From the calculation results, the band gap of anatase TiO2and Y3+doped TiO2are about 2.15eV and 0.86eV. The calculated results demonstrated that the mixing of Yttrium (Y) dopants induces states with original titanium 3d and oxygen 2p valence band attributes to the band gap narrowing. This can enhance the photocatalytic activity of anatase TiO2.

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26

Pan, Haijun, Xiangying Meng, Dongyan Liu, Song Li i Gaowu Qin. "(Ti/Zr,N) codoped hematite for enhancing the photoelectrochemical activity of water splitting". Physical Chemistry Chemical Physics 17, nr 34 (2015): 22179–86. http://dx.doi.org/10.1039/c5cp01489a.

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In this theoretical study, first-principles calculations were carried out to explore the photocatalytic activity of cation (Ti or Zr) and anion (N) compensated codoped hematite based on density functional theory (DFT).

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Hill, Quintin, i Chris-Kriton Skylaris. "Including dispersion interactions in the ONETEP program for linear-scaling density functional theory calculations". Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 465, nr 2103 (9.12.2008): 669–83. http://dx.doi.org/10.1098/rspa.2008.0398.

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While density functional theory (DFT) allows accurate quantum mechanical simulations from first principles in molecules and solids, commonly used exchange-correlation density functionals provide a very incomplete description of dispersion interactions. One way to include such interactions is to augment the DFT energy expression by damped London energy expressions. Several variants of this have been developed for this task, which we discuss and compare in this paper. We have implemented these schemes in the ONETEP program, which is capable of DFT calculations with computational cost that increases linearly with the number of atoms. We have optimized all the parameters involved in our implementation of the dispersion correction, with the aim of simulating biomolecular systems. Our tests show that in cases where dispersion interactions are important this approach produces binding energies and molecular structures of a quality comparable with high-level wavefunction-based approaches.

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Arif Khalil, R. M., Javed Ahmad, Anwar Manzoor Rana, Syed Hamad Bukhari, M. Tufiq Jamil, Tuba Tehreem i Umair Nissar. "First principles investigation of structural, vibrational and thermal properties of black and blue phosphorene". International Journal of Modern Physics B 32, nr 12 (3.05.2018): 1850151. http://dx.doi.org/10.1142/s0217979218501515.

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In this investigation, structural, dynamical and thermal properties of black and blue phosphorene (P) are presented through the first principles calculations based on the density functional theory (DFT). These DFT calculations depict that due to the approximately same values of ground state energy at zero Kelvin and Helmholtz free energy at room-temperature, it is expected that both structures can coexist at transition temperature. Lattice dynamics of both phases were investigated by using the finite displacement supercell approach. It is noticed on the basis of harmonic approximation thermodynamic calculations that the blue phase is thermodynamically more stable than the black phase above 155 K.

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Nguyen-Thuy, Trang, Phong Le-Hoang, Nam Hoang Vu, Thong Nguyen-Minh Le, Tan Le Hoang Doan, Jer-Lai Kuo, Toan T. Nguyen, Thang Bach Phan i Duc Nguyen-Manh. "Hydrogen adsorption mechanism of MOF-74 metal–organic frameworks: an insight from first principles calculations". RSC Advances 10, nr 72 (2020): 43940–49. http://dx.doi.org/10.1039/d0ra08864a.

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The microscopic mechanism of the H₂ adsorption of two Mg-MOF-74 isoreticular frameworks, one with a benzenedicarboxylate linker and the other with a dihydroxyfumarate linker, were studied on the basis of density functional theory (DFT) method.

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Sarantuya, Nasantogtokh, Xin Cui i Zhi Ping Wang. "First-principles study of hydrogen diffusion in transition metal palladium". Modern Physics Letters B 29, nr 13 (18.05.2015): 1550064. http://dx.doi.org/10.1142/s0217984915500645.

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By adopting the first-principles total energy calculations based on density functional theory (DFT), the diffuse pattern and path of hydrogen in bulk palladium are investigated by calculating the system energy of hydrogen atom occupying different positions in palladium crystal lattice. The results indicate that the most stable position of hydrogen atom in palladium crystal lattice locates at the octahedral interstice, and the tetrahedral interstice is the second stable site. Hydrogen diffusion along the indirect octahedral–tetrahedral–octahedral (O–T–O) path is energetically most favorable in transition metal palladium, and the activation energy is 0.5245 eV.

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Śpiewak, P., Krzysztof Jan Kurzydlowski, Koji Sueoka, Igor Romandic i Jan Vanhellemont. "First Principles Calculations of the Formation Energy of the Neutral Vacancy in Germanium". Solid State Phenomena 131-133 (październik 2007): 241–46. http://dx.doi.org/10.4028/www.scientific.net/ssp.131-133.241.

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Density functional theory (DFT) with local density approximation has been used to calculate the formation energy (EF) of the neutral vacancy in germanium single crystal. It was shown that careful checking of convergence with respect to the number of k-points is necessary when calculating the formation energy of the intrinsic point defects in Ge. The formation energy of the single neutral vacancy was estimated at 2.35 eV which is in excellent agreement with published experimental data.

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Mahida, H. R., Deobrat Singh, Yogesh Sonvane, Sanjeev K. Gupta, P. B. Thakor i Rajeev Ahuja. "Hydrogenation and oxidation enhances the thermoelectric performance of Si2BN monolayer". New Journal of Chemistry 45, nr 8 (2021): 3892–900. http://dx.doi.org/10.1039/d0nj06000c.

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In the present study, we have investigated the structural, electronic, and charge transport properties of pristine, hydrogenated, and oxidized Si₂BN monolayers via first-principles calculations based on density functional theory (DFT).

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Li, Hongshan, Yong Cao, Shenggang Zhou, Peixian Zhu i Jingchuan Zhu. "Site preferences and effects of X (X = Mn, Fe, Co, Cu) on the properties of NiAl: A first-principles study". Modern Physics Letters B 30, nr 09 (10.04.2016): 1650133. http://dx.doi.org/10.1142/s0217984916501335.

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The site preference of X (X = Mn, Fe, Co, Cu) in NiAl and its effects on structural, electronic and elastic properties were investigated by performing first-principles calculations using density functional theory (DFT). Formation enthalpy calculations show that adding X increases the formation enthalpy of NiAl, indicating that X addition reduces the stability of system. The site preference was investigated by calculating the transfer energy of NiAl alloys with X. The results further exhibit that Mn, Fe and Cu show no site preference, but Co tends to occupy Ni site. By analyzing electronic density of states, Mulliken population, overlap population and valence charge density, the electronic property and bond characters were discussed. The elastic property calculation shows that only substitution of Ni by Cu increased the plasticity of alloy, while in the other cases the plasticity was decreased.

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Csо́rе́, Andras, Björn Magnusson, Nguyen Tien Son, Andreas Gällström, Takeshi Ohshima, Ivan Ivanov i Ádám Gali. "First-Principles Study on Photoluminescence Quenching of Divacancy in 4H SiC". Materials Science Forum 963 (lipiec 2019): 714–17. http://dx.doi.org/10.4028/www.scientific.net/msf.963.714.

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In this work, quenching effect in the photoluminescence (PL) spectrum of divacancy defects in 4H SiC is investigated. Quenching in PL occurs when photoexcitation with an energy below a certain threshold is applied. In order to understand this phenomenon, we carried out Kohn-Sham density functional theory (DFT) calculations. In accordance with recent experimental results, we propose a physical model which explains the quenching phenomenon.

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35

Tan, Hong Lin, Cong Ying Jia, Xiao Xu Ge i Chao Xiang. "First-Principles Conductance Calculations of Ag-Al Co-Doped ZnO". Advanced Materials Research 468-471 (luty 2012): 1726–31. http://dx.doi.org/10.4028/www.scientific.net/amr.468-471.1726.

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Based on Density Functional Theory (DFT) first-principles plane-wave ultra-soft pseudo-potential method, we calculated the electronic structure of wurtzite ZnO, Ag-doped ZnO and Ag-Al co-doped ZnO. And we anglicized of energy band structure, electron density of states of Ag-doped and Ag- Al co-doped ZnO crystal. The results indicated: Ag-doped ZnO introduced the deep accepter level in the energy gap, carrier (hole) located near the top of the valence band. And when we add active donor Al to the Ag-Al doped ZnO, the main level moved to low-energy, forming a shallow acceptor level. Meanwhile, the acceptor level got wider, non-localized features got significantly, improving the doping concentration and stability of the system.

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36

Schmid, Rochus, i Tom Ziegler. "Ethylene-polymerization by surface supported Cr(IV) species: possible reaction mechanisms revisited by theoretical calculations". Canadian Journal of Chemistry 78, nr 2 (6.02.2000): 265–69. http://dx.doi.org/10.1139/v99-242.

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Possible reaction mechanisms of olefin polymerization catalyzed by surface supported Cr(IV) species have been investigated by first principles density functional theory (DFT). Pathways starting from neutral alkylidene or bisalkyl complexes were found to suffer from high ethylene insertion barriers, whereas a cationic system formed by protonation of the alkylidene show a low barrier for chain propagation.Key words: density functional theory, alkylidene, olefin polymerization, Cr(IV) species.

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37

Li, Longhua, Jianli Mi, Yangchun Yong, Baodong Mao i Weidong Shi. "First-principles study on the lattice plane and termination dependence of the electronic properties of the NiO/CH3NH3PbI3 interfaces". Journal of Materials Chemistry C 6, nr 30 (2018): 8226–33. http://dx.doi.org/10.1039/c8tc01974f.

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Density functional theory (DFT) and non-equilibrium Green's function (NEGF) calculations give an insight at an atomistic level into the structure–property relationship of the nickel oxide/organometal halide perovskite (NiO/MAPbI₃) interface.

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BOUAMAMA, K., i P. DJEMIA. "THEORETICAL INVESTIGATION OF THE ELASTIC PROPERTIES AND LATTICE DYNAMICS OF THE MgSxSe1-x ALLOY". Modern Physics Letters B 21, nr 05 (20.02.2007): 249–59. http://dx.doi.org/10.1142/s0217984907012621.

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Structural and elastic properties as well as lattice dynamics of ternary MgS x Se 1-x alloy have been studied using first-principles calculations. These are done using density functional theory (DFT) and density functional perturbation theory (DFPT) within the local density approximation (LDA) and employing the virtual-crystal approximation (VCA). We found that the lattice parameter, the elastic constants and the phonon frequencies follow a quadratic law in x.

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Ikehata, H., N. Nagasako, S. Kuramoto i T. Saito. "Designing New Structural Materials Using Density Functional Theory: The Example of Gum MetalTM". MRS Bulletin 31, nr 9 (wrzesień 2006): 688–92. http://dx.doi.org/10.1557/mrs2006.178.

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AbstractAs an example of the application of density functional theory (DFT) to materials design, we describe our use of ab initio calculations based on DFT to develop a new structural material: Gum MetalTM, a novel, multifunctional titanium alloy with a low Young's modulus and high strength. We first carried out calculations on elastic constants in several Ti-X binary alloys to obtain the basic principles on which to determine the compositional limitations of an alloy with a low modulus. The elastic properties in the Ti-based binary alloys were successfully estimated by ab initio calculations, with the result implying absolute elastic softening at the valence electron number per atom, e/a, of 4.24. We also studied the effects of additional elements experimentally and, by comparison with electronic-structure calculations, found two more key parameters (approximately representing bond strength and electronegativity), critical for the design of practical elastic properties. We discuss dislocation-free plastic deformation of Gum Metal and its relation to the absolute elastic softening at an e/a value of 4.24, and finally we discuss the prospects for future applications of DFT in structural materials.

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40

Xiao, Haibo, Xiaonan Wang, Ruilong Wang, Lingfang Xu, Shiheng Liang i Changping Yang. "Intrinsic magnetism and biaxial strain tuning in two-dimensional metal halides V3X8 (X = F, Cl, Br, I) from first principles and Monte Carlo simulation". Physical Chemistry Chemical Physics 21, nr 22 (2019): 11731–39. http://dx.doi.org/10.1039/c9cp00850k.

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A novel family of two-dimensional (2D) crystalline metal superhalogens V₃X₈ (X = F, Cl, Br, I) with intrinsic magnetism was predicted using first-principles calculations in the framework of density functional theory (DFT).

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41

YE, HONGJUN, RUIZHI ZHANG, DAWEI WANG, YU CUI, JIE WEI, CHUNLEI WANG, ZHUO XU, SHAOBO QU i XIAOYONG WEI. "FIRST-PRINCIPLES CALCULATION OF LEAD-FREE PEROVSKITE SnTiO3". International Journal of Modern Physics B 27, nr 24 (11.09.2013): 1350144. http://dx.doi.org/10.1142/s0217979213501440.

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The phonon spectra, band structure and density of states of cubic perovskite SnTiO 3 were investigated using first-principles density functional theory (DFT) computation. The potential energy curves of cations displacement and the formation energy of Sn substitution to B-site were calculated to estimate the structure stability. The results indicate that perovskite SnTiO 3 is a promising ferroelectric end member for lead-free piezoelectric materials and applications.

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42

Rauwolf, Cordula, Achim Mehlhorn i Jürgen Fabian. "Binding Energies of Organic Charge-Transfer Complexes Calculated by First-Principles Methods". Collection of Czechoslovak Chemical Communications 63, nr 8 (1998): 1223–44. http://dx.doi.org/10.1135/cccc19981223.

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Weak interactions between organic donor and acceptor molecules resulting in cofacially-stacked aggregates ("CT complexes") were studied by second-order many-body perturbation theory (MP2) and by gradient-corrected hybrid Hartree-Fock/density functional theory (B3LYP exchange-correlation functional). The complexes consist of tetrathiafulvalene (TTF) and related compounds and tetracyanoethylene (TCNE). Density functional theory (DFT) and MP2 molecular equilibrium geometries of the component structures are calculated by means of 6-31G*, 6-31G*(0.25), 6-31++G**, 6-31++G(3df,2p) and 6-311G** basis sets. Reliable molecular geometries are obtained for the donor and acceptor compounds considered. The geometries of the compounds were kept frozen in optimizing aggregate structures with respect to the intermolecular distance. The basis set superposition error (BSSE) was considered (counterpoise correction). According to the DFT and MP2 calculations laterally-displaced stacks are more stable than vertical stacks. The charge transfer from the donor to the acceptor is small in the ground state of the isolated complexes. The cp-corrected binding energies of TTF/TCNE amount to -1.7 and -6.3 kcal/mol at the DFT(B3LYP) and MP2(frozen) level of theory, respectively (6-31G* basis set). Larger binding energies were obtained by Hobza's 6-31G*(0.25) basis set. The larger MP2 binding energies suggest that the dispersion energy is underestimated or not considered by the B3LYP functional. The energy increases when S in TTF/TCNE is replaced by O or NH but decreases with substitution by Se. The charge-transferred complexes in the triplet state are favored in the vertical arrangement. Self-consistent-reaction-field (SCRF) calculations predicted a gain in binding energy with solvation for the ground-state complex. The ground-state charge transfer between the components is increased up to 0.8 e in polar solvents.

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Kumar, S., Durgesh Kumar Sharma i S. Auluck. "Band gap engineering of ZnO substituted with nitrogen and fluorine, ZnO1−3xN2xFx: a hybrid density functional study". RSC Advances 6, nr 101 (2016): 99088–95. http://dx.doi.org/10.1039/c6ra17693c.

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A series of first principles calculations within density functional theory (DFT) have been performed for ZnO, co-doped with N and F with the aim of engineering the band gap and improving its application to photo-absorption activity.

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44

Alaal, Naresh, Nikhil Medhekar i Alok Shukla. "Tunable electronic properties of partially edge-hydrogenated armchair boron–nitrogen–carbon nanoribbons". Physical Chemistry Chemical Physics 20, nr 15 (2018): 10345–58. http://dx.doi.org/10.1039/c7cp08234g.

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We employ a first-principles calculations based density-functional-theory (DFT) approach to study the electronic properties of partially and fully edge-hydrogenated armchair boron–nitrogen–carbon (BNC) nanoribbons (ABNCNRs), with widths between 0.85 nm to 2.3 nm.

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45

Liu, Shan, i Ziran Liu. "Hybridization induced metallic and magnetic edge states in noble transition-metal-dichalcogenides of PtX2 (X = S, Se) nanoribbons". Physical Chemistry Chemical Physics 20, nr 33 (2018): 21441–46. http://dx.doi.org/10.1039/c8cp03640c.

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In the present work, a nanoribbon with two parallel metallic and magnetic edges was designed from a noble TMD 1T-PtX₂ (X = S, Se) by employing first-principles calculations based on density functional theory (DFT).

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46

Xu, Rui Qing, Lan Fang Yao, Lin Li, Shuo Wang, Lin Lin Tian i Xue Ling Fang. "First-Principles Calculations on Pure and Ga-Doped Anatase TiO₂". Advanced Materials Research 156-157 (październik 2010): 1385–88. http://dx.doi.org/10.4028/www.scientific.net/amr.156-157.1385.

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First-principles calculations using the plane-wave pseudo-potential (PWPP) method based on the density functional theory (DFT) is employed to study the crystal structure, band gap, density of states of anatase TiO2 doped with gadolinium (Gd). The generalized gradient approximation (GGA) based on exchange-correlation energy optimization is employed to calculate them. The calculated results demonstrate that the mixing of gadolinium dopants induces states with original titanium 3d and oxygen 2p valence band attributes to the band gap narrowing. This can enhance the photocatalytic activity of anatase TiO2.

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Bhatt, Nisarg K., A. B. Patel, A. Y. Vahora, P. R. Vyas, B. Y. Thakore i Ashvin R. Jani. "Structural and Vibrational Properties of FeO Using First-Principles". Advanced Materials Research 665 (luty 2013): 49–52. http://dx.doi.org/10.4028/www.scientific.net/amr.665.49.

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We have studied the equation of states and vibrational properties of FeO using DFT based plane-wave pseudopotential (PW-DFT) within the generalized gradient approximation. The calculated cohesive properties at ambient condition, namely, lattice constant (a0), bulk modulus (B0) and its first pressure derivative (), are reported for B1-phase of FeO, in agreement with previous experimental and other theoretical results. A linear-response approach to the density functional theory was used to derive the phonon frequencies and phonon density of state (p-dos). Further, in order to calculate both static and dynamic equations of states, nearest-neighbour second-moment tight-binding energy model (TB-SMA) was used. Parameters of the present TB-SMA model were determined by the presentab initiopseudopotential calculations. It is found that the present simple TB-SMA scheme is able to mimic shock Hugoniot for such oxides correctly.

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Wei, Yun, Ben Niu, Qijun Liu, Zhengtang Liu i Chenglu Jiang. "First-Principles Calculations of Structural and Mechanical Properties of Cu–Ni Alloys". Crystals 13, nr 1 (26.12.2022): 43. http://dx.doi.org/10.3390/cryst13010043.

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Nanostructured Cu–Ni alloys have become the focus of public attention due to their better corrosion resistance and high hardness in experimental measurements. First-principles calculation based on the density functional theory (DFT) has been confirmed as an effective tool and used to illustrate the mechanical properties of these alloys. In this paper, the DFT has been employed to calculate the mechanical properties of Cu–Ni alloys, including bulk modulus, shear modulus, Young’s modulus, anisotropic index, Poisson’s ratio, average velocity, and B/G. We find that the Ni-rich Cu–Ni alloys have relatively higher mechanical parameters, and the Cu-rich alloys have smaller mechanical parameters, which is consistent with previous experiments. This provides an idea for us to design alloys to improve alloy strength.

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YANG, LI, HANKUI LIU i XIAOTAO ZU. "FIRST-PRINCIPLES STUDY OF THE MIGRATION OF HELIUM IN TUNGSTEN". International Journal of Modern Physics B 23, nr 08 (30.03.2009): 2077–82. http://dx.doi.org/10.1142/s0217979209049334.

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First-principles calculations based on density functional theory (DFT) within the generalized gradient approximation (GGA) have been carried out to study the migration of helium in tungsten. The results show that helium interstitial jump directly between two tetrahedral sites with very low migration energy. The migration manner of interstitial He is related to the configuration of the host metal. Furthermore, the dissociation energy of a substitutional helium atom from a vacancy has been calculated from first-principles.

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Kato, Reizo, i Takao Tsumuraya. "Dirac Cone Formation in Single-Component Molecular Conductors Based on Metal Dithiolene Complexes". Magnetochemistry 9, nr 7 (6.07.2023): 174. http://dx.doi.org/10.3390/magnetochemistry9070174.

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Single-component molecular conductors exhibit a strong connection to the Dirac electron system. The formation of Dirac cones in single-component molecular conductors relies on (1) the crossing of HOMO and LUMO bands and (2) the presence of nodes in the HOMO–LUMO couplings. In this study, we investigated the possibility of Dirac cone formation in two single-component molecular conductors derived from nickel complexes with extended tetrathiafulvalenedithiolate ligands, [Ni(tmdt)2] and [Ni(btdt)2], using tight-biding models and first-principles density-functional theory (DFT) calculations. The tight-binding model predicts the emergence of Dirac cones in both systems, which is associated with the stretcher bond type molecular arrangement. The DFT calculations also indicate the formation of Dirac cones in both systems. In the case of [Ni(btdt)2], the DFT calculations, employing a vdW-DF2 functional, reveal the formation of Dirac cones near the Fermi level in the nonmagnetic state after structural optimization. Furthermore, the DFT calculations, by utilizing the range-separated hybrid functional, confirm the antiferromagnetic stability in [Ni(btdt)2], as observed experimentally.

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