scholarly journals Insights from Systematic DFT Calculations on Superconductors

2021 ◽  
Author(s):  
Ian D.R. Mackinnon ◽  
Alanoud Almutairi ◽  
Jose A. Alarco
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Optimal Level ◽  
Reciprocal Space ◽  
Boron Doped Diamond ◽  
Functional Theory ◽  
Fermi Surfaces ◽  
Boron Doped ◽  
Space Separation ◽  
Phonon Anomaly

We present three systematic approaches to use of Density Functional Theory (DFT) for interpretation and prediction of superconductivity in new or existing materials. These approaches do not require estimates of free parameters but utilize standard input values that significantly influence computational resolution of reciprocal space Fermi surfaces and that reduce the meV-scale energy variability of calculated values. Systematic calculations on conventional superconductors show that to attain a level of resolution comparable to the energy gap, two key parameters, Δk and the cut-off energy, must be optimized for a specific compound. The optimal level of resolution is achieved with k-grids smaller than the minimum reciprocal space separation between key parallel Fermi surfaces. These approaches enable estimates of superconducting properties including the transition temperature (Tc) via (i) measurement of the equivalent thermal energy of a phonon anomaly (if present), (ii) the distribution of electrons and effect on Fermi energy (EF) when subjected to a deformation potential and (iii) use of parabolic, or higher order quartic, approximations for key electronic bands implicated in electron–phonon interactions. We demonstrate these approaches for the conventional superconductors MgB2, metal substituted MgB2 and boron-doped diamond.

The origin of shallow n-type conductivity in boron-doped diamond with H or S co-doping: Density functional theory study

2006 ◽  
Vol 15 (11-12) ◽  
pp. 1868-1877 ◽  
Author(s):  
Yu Cai ◽  
Tianhou Zhang ◽  
Alfred B. Anderson ◽  
John C. Angus ◽  
Lubomir N. Kostadinov ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Study ◽  
Boron Doped Diamond ◽  
Doping Density ◽  
Functional Theory ◽  
Type Conductivity ◽  
Co Doping ◽  
Boron Doped

scholarly journals DFT studies of refractive index of boron-doped diamond

2018 ◽  
Vol 10 (2) ◽  
pp. 39 ◽  
Author(s):  
Bartłomiej Dec ◽  
Robert Bogdanowicz
Keyword(s):  
Density Functional Theory ◽  
Ab Initio ◽  
Density Functional ◽  
Fused Silica ◽  
Band Gaps ◽  
Optical And Electrical Properties ◽  
Boron Doped Diamond ◽  
Functional Theory ◽  
Long Period ◽  
Boron Doped

The density functional theory is one of the optimal solutions in calculation of optical properties of materials on the quantum scale. In this paper, we have investigated refractive index of a boron-doped diamond structure with the usage of Atomistic Toolkit software from Synopsys. During this study, various methods and pseudopotentials were checked to obtain an optimal performance-accuracy method for calculation of such materials. Leading method used in calculation was used meta-GGA with Fritz-Haber Institute pseudopotential. Full Text: PDF ReferencesW. Kohn and L. J. Sham, "Self-Consistent Equations Including Exchange and Correlation Effects", Phys. Rev., vol. 140, no. 4A, pp. A1133–A1138 (1965). CrossRef J. P. Perdew, K. Burke, and M. Ernzerhof, "Generalized Gradient Approximation Made Simple", Phys. Rev. Lett., vol. 77, no. 18, pp. 3865–3868 (1996). CrossRef Y. Yan, J. Gong, and Z. Zong, "Superconductivity of p-type diamond (001) and (111) thin films: Ab initio calculations", Thin Solid Films, vol. 518, no. 17, pp. 4989–4996 (2010). CrossRef M. P. Desjarlais, "Density functional calculations of the reflectivity of shocked xenon with ionization based gap corrections", Contributions to Plasma Physics, vol. 45, no. 3–4, pp. 300–304 (2005). CrossRef L. G. Ferreira, M. Marques, and L. K. Teles, "Approximation to density functional theory for the calculation of band gaps of semiconductors", Physical Review B, vol. 78, no. 12, (2008). CrossRef J. M. Soler et al., "The SIESTA method for ab initio order- N materials simulation", Journal of Physics: Condensed Matter, vol. 14, no. 11, pp. 2745–2779 (2002). CrossRef L. Kleinman and D. M. Bylander, "Efficacious Form for Model Pseudopotentials", Phys. Rev. Lett., vol. 48, no. 20, pp. 1425–1428 (1982). CrossRef Synopsys QuantumWise, Atomistix Toolkit version 2017.12.F. Tran and P. Blaha, "Accurate Band Gaps of Semiconductors and Insulators with a Semilocal Exchange-Correlation Potential", Phys. Rev. Lett., vol. 102, no. 22, p. 226401 (2009). CrossRef D. R. Lide, Ed., CRC Handbook of Chemistry and Physics, 83rd Edition, Boca Raton, Fla.: CRC Press, 2002.N. Troullier and J. L. Martins, "Efficient pseudopotentials for plane-wave calculations", Phys. Rev. B, vol. 43, no. 3, pp. 1993–2006 (1991). CrossRef W. A. Harrison, Solid state theory. McGraw-Hill, 1970.M. Sobaszek et al., "Optical and electrical properties of ultrathin transparent nanocrystalline boron-doped diamond electrodes", Optical Materials, vol. 42, pp. 24–34 (2015). CrossRef M. Ficek et al., "Optical and electrical properties of boron doped diamond thin conductive films deposited on fused silica glass substrates", Applied Surface Science, vol. 387, pp. 846–856 (2016). CrossRef R. Maezono, A. Ma, M. D. Towler, and R. J. Needs, "Equation of State and Raman Frequency of Diamond from Quantum Monte Carlo Simulations", Phys. Rev. Lett., vol. 98, no. 2, p. 025701 (2007). CrossRef R. Bogdanowicz et al., "Opto-Electrochemical Sensing Device Based on Long-Period Grating Coated with Boron-Doped Diamond Thin Film", J. Opt. Soc. Korea, JOSK, vol. 19, no. 6, pp. 705–710, (2015). CrossRef M. Ficek et al., "Linear antenna microwave chemical vapour deposition of diamond films on long-period fiber gratings for bio-sensing applications", Opt. Mater. Express, OME, vol. 7, no. 11, pp. 3952–3962 (2017). CrossRef M. Ficek, R. Bogdanowicz, and J. Ryl, "Nanocrystalline CVD Diamond Coatings on Fused Silica Optical Fibres: Optical Properties Study", Acta Physica Polonica A, vol. 127, no. 3, pp. 868–873 (2015). CrossRef P. J. Stephens, F. J. Devlin, C. F. Chabalowski, and M. J. Frisch, "Ab Initio Calculation of Vibrational Absorption and Circular Dichroism Spectra Using Density Functional Force Fields", J. Phys. Chem., vol. 98, no. 45, pp. 11623–11627 (1994). CrossRef P. Rivero, W. Shelton, and V. Meunier, "Surface properties of hydrogenated diamond in the presence of adsorbates: A hybrid functional DFT study", Carbon, vol. 110, pp. 469–479 (2016). CrossRef

scholarly journals Ab-initio study of electrical and optical properties of allylamine

2018 ◽  
Vol 10 (3) ◽  
pp. 94 ◽  
Author(s):  
Bartłomiej Dec ◽  
Robert Bogdanowicz ◽  
Krzysztof Pyrchla
Keyword(s):  
Density Functional Theory ◽  
Refractive Index ◽  
Optical Properties ◽  
Density Functional ◽  
Band Gaps ◽  
Functional Study ◽  
Boron Doped Diamond ◽  
Electrical And Optical Properties ◽  
Functional Theory ◽  
Boron Doped

The Density functional theory is one of most promising methodology in fast and accurate calculations of electrical and optical properties from the atomic basis. In this paper, we calculate electrical and optical properties of allylamine (2-propen 1- amine) in terms of accuracy and speed of calculations obtained by selection of DFT-1/2 method with ultrasoft Vanderbilt pseudopotentials. Comparison of density of states between molecule and bulk configuration shows great agreement between them, therefore we calculated refractive index which showed even better agreement with experimental data. Full Text: PDF ReferencesW. Kohn and L. J. Sham, 'Self-Consistent Equations Including Exchange and Correlation Effects', Phys. Rev., vol. 140, no. 4A, pp. A1133–A1138, Nov. 1965. CrossRef J. P. Perdew, K. Burke, and M. Ernzerhof, 'Generalized Gradient Approximation Made Simple', Phys. Rev. Lett., vol. 77, no. 18, pp. 3865–3868, Oct. 1996. CrossRef L. G. Ferreira, M. Marques, and L. K. Teles, 'Approximation to density functional theory for the calculation of band gaps of semiconductors', Physical Review B, vol. 78, no. 12, Sep. 2008. CrossRef L. G. Ferreira, M. Marques, and L. K. Teles, 'Slater half-occupation technique revisited: the LDA-1/2 and GGA-1/2 approaches for atomic ionization energies and band gaps in semiconductors', AIP Advances, vol. 1, no. 3, p. 032119, Aug. 2011. CrossRef M. Schlipf and F. Gygi, 'Optimization algorithm for the generation of ONCV pseudopotentials', Computer Physics Communications, vol. 196, pp. 36–44, Nov. 2015. CrossRef P. Prayongpan and C. Michael Greenlief, 'Density functional study of ethylamine and allylamine on Si(100)-2×1 and Ge(100)-2×1 surfaces', Surface Science, vol. 603, no. 7, pp. 1055–1069, Apr. 2009. CrossRef M. T. van Os, B. Menges, R. Foerch, G. J. Vancso, and W. Knoll, 'Characterization of Plasma-Polymerized Allylamine Using Waveguide Mode Spectroscopy', Chemistry of Materials, vol. 11, no. 11, pp. 3252–3257, Nov. 1999. CrossRef J. Zeng, R.-Q. Zhang, and H. Treutlein, Quantum Simulations of Materials and Biological Systems. Springer Science & Business Media, 2012. CrossRef I. Del Villar, I. R. Matias, and F. J. Arregui, 'Enhancement of sensitivity in long-period fiber gratings with deposition of low-refractive-index materials', Optics Letters, vol. 30, no. 18, p. 2363, Sep. 2005. CrossRef D. Nidzworski et al., 'A rapid-response ultrasensitive biosensor for influenza virus detection using antibody modified boron-doped diamond', Sci Rep, vol. 7, Nov. 2017. CrossRef Synopsys QuantumWise, Atomistix Toolkit version 2018.06 .D. C. Liu and J. Nocedal, 'On the limited memory BFGS method for large scale optimization', Mathematical Programming, vol. 45, no. 1–3, pp. 503–528, Aug. 1989. CrossRef K. F. Garrity, J. W. Bennett, K. M. Rabe, and D. Vanderbilt, 'Pseudopotentials for high-throughput DFT calculations', Computational Materials Science, vol. 81, pp. 446–452, Jan. 2014. CrossRef Yu Cai, T. Zhang, A. B. Anderson, J. C. Angus, L. N. Kostadinov, and T. V. Albu, 'The origin of shallow n-type conductivity in boron-doped diamond with H or S co-doping: Density functional theory study', Diamond and Related Materials, vol. 15, no. 11, pp. 1868–1877, Nov. 2006. CrossRef

Molecular Investigations of the Newly Synthesized Azomethines as Antioxidants: Theoretical and Experimental Studies

2019 ◽  
Vol 19 (6) ◽  
pp. 419-433 ◽  
Author(s):  
Siyamak Shahab ◽  
Masoome Sheikhi ◽  
Liudmila Filippovich ◽  
Evgenij Dikusar ◽  
Anhelina Pazniak ◽  
...  
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Experimental Studies ◽  
Antioxidant Property ◽  
Nbo Analysis ◽  
Antioxidant Potential ◽  
Functional Theory ◽  
Homo And Lumo ◽  
Intramolecular Hydrogen ◽  
Activity Mechanism

: In this study, the antioxidant property of new synthesized azomethins has been investigated as theoretical and experimental. Methods and Results: Density functional theory (DFT) was employed to investigate the Bond Dissociation Enthalpy (BDE), Mulliken Charges, NBO analysis, Ionization Potential (IP), Electron Affinities (EA), HOMO and LUMO energies, Hardness (η), Softness (S), Electronegativity (µ), Electrophilic Index (ω), Electron Donating Power (ω-), Electron Accepting Power (ω+) and Energy Gap (Eg) in order to deduce scavenging action of the two new synthesized azomethines (FD-1 and FD-2). Spin density calculations and NBO analysis were also carried out to understand the antioxidant activity mechanism. Comparison of BDE of FD-1 and FD-2 indicate the weal antioxidant potential of these structures. Conclusion: FD-1 and FD-2 have very high antioxidant potential due to the planarity and formation of intramolecular hydrogen bonds.

scholarly journals Exo⇔Endo Isomerism, MEP/DFT, XRD/HSA-Interactions of 2,5-Dimethoxybenzaldehyde: Thermal, 1BNA-Docking, Optical, and TD-DFT Studies

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5970
Author(s):  
Nabil Al-Zaqri ◽  
Mohammed Suleiman ◽  
Anas Al-Ali ◽  
Khaled Alkanad ◽  
Karthik Kumara ◽  
...  
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Structural Parameters ◽  
Population Analysis ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Optical Energy Gap ◽  
Functional Theory ◽  
Reactivity Descriptors ◽  
Td Dft

The exo⇔endo isomerization of 2,5-dimethoxybenzaldehyde was theoretically studied by density functional theory (DFT) to examine its favored conformers via sp2–sp2 single rotation. Both isomers were docked against 1BNA DNA to elucidate their binding ability, and the DFT-computed structural parameters results were matched with the X-ray diffraction (XRD) crystallographic parameters. XRD analysis showed that the exo-isomer was structurally favored and was also considered as the kinetically preferred isomer, while several hydrogen-bonding interactions detected in the crystal lattice by XRD were in good agreement with the Hirshfeld surface analysis calculations. The molecular electrostatic potential, Mulliken and natural population analysis charges, frontier molecular orbitals (HOMO/LUMO), and global reactivity descriptors quantum parameters were also determined at the B3LYP/6-311G(d,p) level of theory. The computed electronic calculations, i.e., TD-SCF/DFT, B3LYP-IR, NMR-DB, and GIAO-NMR, were compared to the experimental UV–Vis., optical energy gap, FTIR, and 1H-NMR, respectively. The thermal behavior of 2,5-dimethoxybenzaldehyde was also evaluated in an open atmosphere by a thermogravimetric–derivative thermogravimetric analysis, indicating its stability up to 95 °C.

Density functional theory prediction for diffusion of lithium on boron-doped graphene surface

2011 ◽  
Vol 257 (17) ◽  
pp. 7443-7446 ◽  
Author(s):  
Shuanghong Gao ◽  
Zhaoyu Ren ◽  
Lijuan Wan ◽  
Jiming Zheng ◽  
Ping Guo ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Functional Theory ◽  
Graphene Surface ◽  
Boron Doped ◽  
Doped Graphene
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