Results 251 to 260 of about 1,180,755 (291)

An approach to DFT calculations using standard microprocessors

IBM Journal of Research and Development, 1985
The use of the DFT as an everyday tool is now commonplace, principally due to advances in hardware technology. Special-purpose VLSI chips for signal processing are available. In this paper, we describe an approach which marries the Winograd Fourier Transform Algorithm (WFTA) with a state-of-the-art 16-bit general-purpose microprocessor for the purpose ...
James T. Rayfield, Harvey F. Silverman
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Assessing calculated DFT properties

Science, 2014
Catalysis Density functional theory (DFT) is now widely used to calculate molecular and material properties. DFT's reliability is usually assessed by comparison with experimental values and higher-level theoretical methods. Medford et al. used the BEEF-vdW, an exchange-correlation density functional tailored for surface chemistry, and looked at ...
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13C CPMAS NMR and DFT calculations of anthocyanidins

Solid State Nuclear Magnetic Resonance, 2008
Anthocyanidins, red dyes from flower petals and fruits, are beneficial to human health. They attract considerable attention owing to their strong antioxidant and radical scavenging properties, however they are unstable in solution and available in small amounts only.
M, Wolniak, I, Wawer
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On the position of the potential wall in DFT temporary anion calculations

Physical Chemistry Chemical Physics, 2007
A simple method was recently proposed [D. J. Tozer and F. De Proft, J. Chem. Phys., 2007, 127, 034108] for performing explicit density functional theory (DFT) calculations on temporary anions. The excess electron in the anion is bound by a potential wall, the position of which is determined by a single parameter lambda, chosen to reproduce an ...
Sablon, Nick, De Proft, Frank, Geerlings, Paul, Tozer, D.j.   +3 more
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DFT Calculation of Glycine with Methanols Clusters

Chinese Journal of Chemical Physics, 2009
Density functional theory (DFT) calculations are reported for the structures of neutral and zwitterionic glycine-(CH3OH)n where n = 16. Initial geometries of the clusters of neutral and zwitterionic glycine with 16 methanol molecules are fully optimized at B3LYP/631+G* level of theory.
Hao Zou, Yong-jun Hu, Da Xing
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Vibrational spectra and DFT calculations of squalene

Journal of Molecular Structure, 2013
Abstract The isoprenoid compound squalene is a building block molecule for the production of essential cellular molecules such as membrane sterols, has several therapeutic activities including anticancer properties, and has commercial applications for a variety of industries including the production of cosmetics.
Hye Jin Chun, Taylor L. Weiss, Timothy P. Devarenne, Jaan Laane   +3 more
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DFT Calculations of a Metal-TCNE Complex

AIP Conference Proceedings, 2007
For V[TCNE](x) y(solvent) (TCNE = tetracyanoethylene), the first room-temperature molecular magnet, the mechanism for the strong exchange coupling in the family M[TCNE](x) y(solvent) has remained a ...
Corneliu I. Oprea, Alina Damian, Mihai A. Gîrţu   +2 more
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DFT and HF–DFT calculations of quadrupole coupling constants in molecules

Chemical Physics, 2000
Abstract The efficacy of several DFT and HF–DFT methods for the calculation of 14 N quadrupole coupling constants in molecules has been investigated. Valence triple-zeta quality Pople and Dunning correlation consistent type bases were used.
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Crystal structure and DFT calculations of andrographiside

Journal of Molecular Structure, 2010
Abstract Crystal and molecular structure of a labdane diterpenoid glucoside, andrographiside (1) is determined from 2D-NMR and X-ray diffraction data. The 2D-NMR study indicates that the carbohydrate moiety is in β-linkage and the sugar moiety is linked to C-19 of the aglycon.
Saikat Kumar Seth, Sukdeb Banerjee, Tanusree Kar   +2 more
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DFT calculations of the binding energy of metallocenes

Chemical Physics Letters, 1997
As recently reported by Klopper and Luthi, there is a discrepancy between experiment and high-level quantum chemical calculations as to the value of the heterolytic metal–ligand bond disruption enthalpy of ferrocene. Indeed their ab initio calculations lead to a best estimate of 655 kcal/mol, whereas the experimental value is 635 kcal/mol.
Mayor-Lopez, Maria José, Weber, Jacques
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