Results 221 to 230 of about 89,902 (264)
Some of the next articles are maybe not open access.
DFT Calculation of the Solid Acidity
2010Density functional theory (DFT) is applied to calculate the ammonia desorption energies on zeolites with various framework types and Y zeolites with various exchange cations. The calculated desorption energy is in good agreement with the ammonia IRMS-TPD measurements. Relationships between the acid strength and geometric parameters are found.
Miki Niwa, Naonobu Katada, Kazu Okumura
openaire +1 more source
MP2, DFT and ab initio calculations on thioxanthone
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2011Density functional theory (DFT), HF and MP2 calculations have been carried out to investigate thioxanthone molecule using the standard 6-31+G(d,p) basis set. The results of MP2 calculations show a butterfly structure for thioxanthone. The calculated results show that the predicted geometry can well reproduce the structural parameters.
Alireza Salimi, Beni +3 more
openaire +2 more sources
Lithium Storage on Graphdiyne Predicted by DFT Calculations
The Journal of Physical Chemistry C, 2012Graphdiyne (GD) is a new carbon allotrope, consisting of an sp- and sp -hybridized carbon network. In this work, density functional theory calculations are carried out to investigate the adsorption and diffusion of lithium (Li) atoms on GD monolayers, and the results are compared with those for graphyne and graphene monolayers. High-capacity Li storage,
Sun, Chenghua, Searles, Debra J.
openaire +4 more sources
Vibrational spectra and DFT calculations of PPV-oligomers
Journal of Molecular Structure, 2003The first two members of the p-phenylenevinylene- oligomer family (i. e. 1, 4-distyrylbenzene [DSB] and 4, 4'-distyrylstilbene [DSS]) were synthesized and their infrared and Raman spectra recorded and empirically assigned. Molecular geometries were optimized for the planar point group (C2h) by the density functional theory (DFT) method using the B3LYP ...
Hrenar, Tomica +4 more
openaire +2 more sources
Whither the density in DFT calculations?
Science, 2017Theoretical Chemistry The continuing development of density functional theory (DFT) has greatly expanded the size and complexity of molecules amenable to computationally tractable simulation. The conventional metric of success for new functionals has been the accuracy of their calculated energies.
openaire +2 more sources
An approach to DFT calculations using standard microprocessors
IBM Journal of Research and Development, 1985The 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
openaire +1 more source
13C CPMAS NMR and DFT calculations of anthocyanidins
Solid State Nuclear Magnetic Resonance, 2008Anthocyanidins, 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
openaire +2 more sources
Assessing calculated DFT properties
Science, 2014Catalysis 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 ...
openaire +1 more source
On the position of the potential wall in DFT temporary anion calculations
Physical Chemistry Chemical Physics, 2007A 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 +3 more
openaire +3 more sources
Vibrational spectra and DFT calculations of squalene
Journal of Molecular Structure, 2013Abstract 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 +3 more
openaire +1 more source