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Journal articles on the topic 'Dispersion interaction density'

Author: Grafiati

Published: 4 June 2021

Last updated: 13 February 2022

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1

Becke, Axel D., and Erin R. Johnson. "A density-functional model of the dispersion interaction." Journal of Chemical Physics 123, no. 15 (October 15, 2005): 154101. http://dx.doi.org/10.1063/1.2065267.

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2

Tang, Hong, and Jianmin Tao. "Long-range dispersion-corrected density functional for noncovalent interactions." International Journal of Modern Physics B 33, no. 26 (October 20, 2019): 1950300. http://dx.doi.org/10.1142/s0217979219503004.

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Noncovalent interactions are important in determining structures and properties of molecular complexes and biological molecules, and for understanding adsorption processes in chemistry and biological science, and are still challenging to conventional density functional theories. In this work, the recently developed Tao-Mo (TM) meta-GGA (generalized gradient approximation) functional is combined with the D3 scheme of long-range van der Waals (vdW) interaction correction and the parameters of damping function are optimized with the S66[Formula: see text]×[Formula: see text]8 set. The resulting TM-D3 method is applied to the medium-sized molecular set S22 and large size molecular complexes set L7 to calculate intramolecular interaction energies. The TM-D3 method produces the best accuracy for the S22 set with a MAE of 0.2 kcal/mol, improving upon the PBE-D3 (MAE[Formula: see text]=[Formula: see text]0.5 kcal/mol), PBE0-D3 (MAE[Formula: see text]=[Formula: see text]0.5 kcal/mol), TPSS-D3 (MAE[Formula: see text]=[Formula: see text]0.4 kcal/mol), M06L (MAE[Formula: see text]=[Formula: see text]0.8 kcal/mol), and SCAN-D3 (MAE[Formula: see text]=[Formula: see text]0.4 kcal/mol) methods. For the large size set L7, the TM-D3 (MAE[Formula: see text]=[Formula: see text]2.1 kcal/mol) also performs better than the PBE-D3 (MAE[Formula: see text]=[Formula: see text]2.6 kcal/mol), SCAN-D3 (2.5 kcal/mol) and M06L (3.0 kcal/mol), but not accurate than the PBE0-D3 (MAE[Formula: see text]=[Formula: see text]0.8 kcal/mol) and TPSS-D3 (MAE[Formula: see text]=[Formula: see text]1.1 kcal/mol). However, overall, the TM-D3 method performs very well with an error of 2.7% of mean binding of the S22 set and an error of 12.6% of the mean binding of the L7 set for the two typical and important medium and large size molecular complex sets. The success of the dispersion-corrected TM functional benefits from the ability of the plain TM functional to capture the short-range vdW interaction or extend the short-range interaction to the middle range, and the right coupling between the TM and the long-range vdW correction D3 scheme, leading to the improved description of noncovalent interactions.

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3

BARCI, DANIEL G., C. A. LINHARES, A. F. DE QUEIROZ, and J. F. MEDEIROS NETO. "FUNCTIONAL BOSONIZATION OF NONRELATIVISTIC FERMIONS IN 2+1 DIMENSIONS." International Journal of Modern Physics A 15, no. 29 (November 20, 2000): 4655–79. http://dx.doi.org/10.1142/s0217751x00002032.

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We analyze the universality of the bosonization rules in nonrelativistic fermionic systems in (2+1)d. We show that, in the case of linear fermionic dispersion relations, a general fermionic theory can be mapped into a gauge theory in such a way that the fermionic density maps into a magnetic flux and the fermionic current maps into a transverse electric field. These are universal rules in the sense that they remain valid whatever the interaction considered. We also show that these rules are universal in the case of nonlinear dispersion relations provided we consider only density–density interactions. We apply the functional bosonization formalism to a nonrelativistic and nonlocal massive Thirring-like model and evaluate the spectrum of collective excitations in several limits. In the large mass limit, we are able to exactly calculate this spectrum for arbitrary density–density and current–current interactions. We also analyze the massless case and show that it has no collective excitations for any density–density potential in the Gaussian approximation. Moreover, the presence of current interactions may induce a gapless mode with a linear dispersion relation.

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4

Kooi, Derk Pieter, and Paola Gori-Giorgi. "London dispersion forces without density distortion: a path to first principles inclusion in density functional theory." Faraday Discussions 224 (2020): 145–65. http://dx.doi.org/10.1039/d0fd00056f.

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We analyse a path to construct density functionals for the dispersion interaction energy from an expression in terms of the ground state densities and exchange–correlation holes of the isolated fragments.

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5

Prakash, Ved, Suresh C. Sharma, Vijayshri, and Ruby Gupta. "Surface wave excitation by a density modulated electron beam in a magnetized dusty plasma cylinder." Laser and Particle Beams 31, no. 3 (June 17, 2013): 411–18. http://dx.doi.org/10.1017/s0263034612001048.

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AbstractThis paper studies the surface plasma wave excitation via Cerenkov and fast cyclotron interaction by a density modulated electron beam propagating through a magnetized dusty plasma cylinder. The dispersion relation of surface plasma waves has been derived and it has been shown that the phase velocity of waves increases with increase in relative density δ(= nio/ne0, where ni0 is the ion plasma density and ne0 is the electron plasma density) of negatively charged dust grains. The beam radius is taken slightly less than the radius of dusty plasma cylinder. The frequency and the growth rate of the unstable wave instability increases with increase in the value of δ and normalized frequency ω/ωpe. The growth rate of the instability increases with the beam density and scales as one-third power of the beam density in Cerenkov interaction and square root of beam density in fast cyclotron interaction. The dispersion relation of surface plasma waves has been retrieved from the derived dispersion relation by considering that the beam is absent and there are no dust grains in the plasma cylinder.

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6

Ciuffoli, Emilio, Jarah Evslin, Xiaojun Bi, and Xinmin Zhang. "Neutrino Splitting and Density-Dependent Dispersion Relations." ISRN High Energy Physics 2012 (November 4, 2012): 1–20. http://dx.doi.org/10.5402/2012/436580.

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We show that particles are unstable with respect to a splitting process, which is the quantum analog of the modulational instability in anomalous dispersive media, only when their group velocity exceeds their phase velocity. In the case of a neutrino, when the concavity results from a term E(P)~Pk, the neutrino will decay to two neutrinos and an antineutrino after traveling a distance proportional to E2+3k. Unlike the Cohen-Glashow instability, the splitting instability exists even if all particles involved in the interaction have the same dispersion relations at the relevant energy scales. We show that this instability leads to strong constraints even if the energy E is a function of both the momentum P and also of the background density ρ; for example, we show that it alone would have been sufficient to eliminate any model of the MINOS/OPERA velocity anomaly which modifies the neutrino dispersion relation while leaving those of other particles intact.

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7

Yuan, Chengqian, Haiming Wu, Meiye Jia, Peifeng Su, Zhixun Luo, and Jiannian Yao. "A theoretical study of weak interactions in phenylenediamine homodimer clusters." Physical Chemistry Chemical Physics 18, no. 42 (2016): 29249–57. http://dx.doi.org/10.1039/c6cp04922b.

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Utilizing dispersion-corrected density functional theory (DFT) calculations, we demonstrate the weak intermolecular interactions of phenylenediamine dimer (pdd) clusters, emphasizing the local lowest energy structures and decomposition of interaction energies by natural bond orbital (NBO) and atoms in molecule (AIM) analyses.

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8

Stöhr, Martin, and Alexandre Tkatchenko. "Quantum mechanics of proteins in explicit water: The role of plasmon-like solute-solvent interactions." Science Advances 5, no. 12 (December 2019): eaax0024. http://dx.doi.org/10.1126/sciadv.aax0024.

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Quantum-mechanical van der Waals dispersion interactions play an essential role in intraprotein and protein-water interactions—the two main factors affecting the structure and dynamics of proteins in water. Typically, these interactions are only treated phenomenologically, via pairwise potential terms in classical force fields. Here, we use an explicit quantum-mechanical approach of density-functional tight-binding combined with the many-body dispersion formalism and demonstrate the relevance of many-body van der Waals forces both to protein energetics and to protein-water interactions. In contrast to commonly used pairwise approaches, many-body effects substantially decrease the relative stability of native states in the absence of water. Upon solvation, the protein-water dispersion interaction counteracts this effect and stabilizes native conformations and transition states. These observations arise from the highly delocalized and collective character of the interactions, suggesting a remarkable persistence of electron correlation through aqueous environments and providing the basis for long-range interaction mechanisms in biomolecular systems.

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9

Briggs, Edward A., and Nicholas A. Besley. "Modelling excited states of weakly bound complexes with density functional theory." Phys. Chem. Chem. Phys. 16, no. 28 (2014): 14455–62. http://dx.doi.org/10.1039/c3cp55361b.

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10

Sahu, S., Y. Hardalupas, and A. M. K. P. Taylor. "Interaction of droplet dispersion and evaporation in a polydispersed spray." Journal of Fluid Mechanics 846 (May 3, 2018): 37–81. http://dx.doi.org/10.1017/jfm.2018.247.

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The interaction between droplet dispersion and evaporation in an acetone spray evaporating under ambient conditions is experimentally studied with an aim to understand the physics behind the spatial correlation between the local vapour mass fraction and droplets. The influence of gas-phase turbulence and droplet–gas slip velocity of such correlations is examined, while the focus is on the consequence of droplet clustering on collective evaporation of droplet clouds. Simultaneous and planar measurements of droplet size, velocity and number density, and vapour mass fraction around the droplets, were obtained by combining the interferometric laser imaging for droplet sizing and planar laser induced fluorescence techniques (Sahuet al.,Exp. Fluids, vol. 55, 1673, 2014b, pp. 1–21). Comparison with droplet measurements in a non-evaporating water spray under the same flow conditions showed that droplet evaporation leads to higher fluctuations of droplet number density and velocity relative to the respective mean values. While the mean droplet–gas slip velocity was found to be negligibly small, the vaporization Damköhler number ($Da_{v}$) was approximately ‘one’, which means the droplet evaporation time and the characteristic time scale of large eddies are of the same order. Thus, the influence of the convective effect on droplet evaporation is not expected to be significant in comparison to the instantaneous fluctuations of slip velocity, which refers to the direct effect of turbulence. An overall linearly increasing trend was observed in the scatter plot of the instantaneous values of droplet number density ($N$) and vapour mass fraction ($Y_{F}$). Accordingly, the correlation coefficient of fluctuations of vapour mass fraction and droplet number density ($R_{n\ast y}$) was relatively high (${\approx}0.5$) implying moderately high correlation. However, considerable spread of the$N$versus$Y_{F}$scatter plot along both coordinates demonstrated the influence on droplet evaporation due to turbulent droplet dispersion, which leads to droplet clustering. The presence of droplet clustering was confirmed by the measurement of spatial correlation coefficient of the fluctuations of droplet number density for different size classes ($R_{n\ast n}$) and the radial distribution function (RDF) of the droplets. Also, the tendency of the droplets to form clusters was higher for the acetone spray than the water spray, indicating that droplet evaporation promoted droplet grouping in the spray. The instantaneous group evaporation number ($G$) was evaluated from the measured length scale of droplet clusters (by the RDF) and the average droplet size and spacing in instantaneous clusters. The mean value of$G$suggests an internal group evaporation mode of the droplet clouds near the spray centre, while single droplet evaporation prevails near the spray boundary. However, the large fluctuations in the magnitude of instantaneous values of$G$at all measurement locations implied temporal variations in the mode of droplet cloud evaporation.

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11

Zhechkov, Lyuben, Thomas Heine, Serguei Patchkovskii, Gotthard Seifert, and Helio A. Duarte. "An Efficienta PosterioriTreatment for Dispersion Interaction in Density-Functional-Based Tight Binding." Journal of Chemical Theory and Computation 1, no. 5 (September 2005): 841–47. http://dx.doi.org/10.1021/ct050065y.

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12

Miao, Junjian, Shugui Hua, and Shuhua Li. "Assessment of density functionals on intramolecular dispersion interaction in large normal alkanes." Chemical Physics Letters 541 (July 2012): 7–11. http://dx.doi.org/10.1016/j.cplett.2012.05.067.

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13

Zheng, Kang, Danping Li, Liu Jiang, Xiaowei Li, Changjian Xie, Ling Feng, Jie Qin, Shaosong Qian, and Qiuxiang Pang. "Revisiting stacking interactions in tetrathiafulvalene and selected derivatives using tight-binding quantum chemical calculations and local coupled-cluster method." Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials 77, no. 3 (May 13, 2021): 311–20. http://dx.doi.org/10.1107/s2052520621003085.

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The engineering of supramolecular architectures needs accurate descriptions of the intermolecular interactions in crystal structures. Tetrathiafulvalene (TTF) is an effective building block used in the construction of promising functional materials. The parallel packing of the neutral TTF–TTF system was studied previously using the high-level quantum chemical method, advancing it as a valuable model system. The recently developed tight-binding quantum chemical method GFN2-xTB and local coupled-cluster method DLPNO-CCSD(T) were used to investigate the stacking interactions of TTF and selected derivatives deposited in the Cambridge Structural Database. Using the interaction energy of the TTF–TTF dimer calculated at the CCSD(T)/CBS level as the reference, the accuracies of the two methods are investigated. The energy decomposition analysis within the DLPNO-CCSD(T) framework reveals the importance of dispersion interaction in the TTF-related stacking systems. The dispersion interaction density plot vividly shows the magnitude and distribution of the dispersion interaction, providing a revealing insight into the stacking interactions in crystal structures. The results show that the GFN2-xTB and DLPNO-CCSD(T) methods could achieve accuracy at an affordable computational cost, which would be valuable in understanding the nature of parallel stacking in supramolecular systems.

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14

Ganesan, M., and S. Paranthaman. "Dispersion-corrected density functional theory studies on glycolic acid-metal complexes." Журнал структурной химии 62, no. 8 (2021): 1251–69. http://dx.doi.org/10.26902/jsc_id78515.

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The structure and metal complexation studies using dispersion-corrected density functional theory methods are performed for four stable glycolic acid conformers named SSC, GAC, SAC, and AAT. The condensed Fukui functions are calculated to study the favourable reactive site for metal binding on the glycolic acid conformers. The interaction of alkali metal ions (Na+, K+) with different binding sites (carboxyl, hydroxyl oxygen) of the glycolic acid conformers in the gas phase is investigated at the same level of theory. Our calculations show that the order of stability changes into SSC > AAT > GAC = SAC due to the binding of the metal ion. The relative energy values indicate that the AAT conformer is more stable than the GAC and SAC conformers. This occurs when a metal ion (Na+, K+) is bound with the carboxyl oxygen atom of glycolic acid. The QTAIM, RDG, NCI, ELF, LOL, and NBO analysis are employed in this work to understand the strength of intra- and intermolecular interactions in the glycolic acid metal complexes.

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15

Du, Hongchen, Y. Liu, and J. Liu. "THEORETICAL STUDY ON THE INTERMOLECULAR INTERACTIONS OF 1,1-DIAMINO-2,2-DINITROETHYLENE WITH NH3 AND H2O." Latin American Applied Research - An international journal 49, no. 4 (September 21, 2019): 241–48. http://dx.doi.org/10.52292/j.laar.2019.121.

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Density Functional Theory (DFT) and dispersion-corrected density functional theory (DFT-D) were used to study the intermolecular interactions of 1,1-diamino-2,2-dinitroethylene FOX-7/NH3and FOX-7/H2O supermolecules. The geometries optimized from DFT and DFT-D methods are similar.Six optimized supermolecules were characterized to be local energy minima on potential energy surfaces without imaginary frequencies. The intermolecular interaction energy (binding energy) was calculated with basis set superposition error (BSSE) correction. The largest corrected intermolecular interaction energy is FOX-7/NH3 (-43.76 kJ×mol-1), indicating that the interaction between FOX-7 and NH3 is stronger than that of FOX-7/H2O. The same conclusion is obtained from the studies on the infrared spectrum and frontier orbitals.

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16

Frigenti, Gabriele, Daniele Farnesi, Gualtiero Nunzi Conti, and Silvia Soria. "Nonlinear Optics in Microspherical Resonators." Micromachines 11, no. 3 (March 13, 2020): 303. http://dx.doi.org/10.3390/mi11030303.

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Nonlinear frequency generation requires high intensity density which is usually achieved with pulsed laser sources, anomalous dispersion, high nonlinear coefficients or long interaction lengths. Whispering gallery mode microresonators (WGMRs) are photonic devices that enhance nonlinear interactions and can be exploited for continuous wave (CW) nonlinear frequency conversion, due to their capability of confine light for long time periods in a very small volume, even though in the normal dispersion regime. All signals must be resonant with the cavity. Here, we present a review of nonlinear optical processes in glass microspherical cavities, hollow and solid.

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17

FENG, CHAO, CHENSHENG LIN, XIAOHONG ZHANG, and RUIQIN ZHANG. "π–π INTERACTION IN BENZENE DIMER STUDIED USING DENSITY FUNCTIONAL THEORY AUGMENTED WITH AN EMPIRICAL DISPERSION TERM." Journal of Theoretical and Computational Chemistry 09, supp01 (January 2010): 109–23. http://dx.doi.org/10.1142/s0219633610005578.

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The π–π interactions in various configurations of benzene dimers were studied using a density functional theoretical method augmented with an empirical dispersion term (acronym DFT-D) which is capable of describing long-range dispersive interaction. Compared with the previous CCSD(T) calculations, our approach using PBE functional and polarized triple-ζ quality basis sets provides reasonably accurate binding energies and equilibrium intermolecular geometries of the considered benzene dimer configurations, although the calculations are not counterpoisely corrected. It is expected that our approach can be utilized to evaluate the π–π interactions in large complex systems.

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18

Song, Yang, Omololu Akin-Ojo, and Feng Wang. "Correcting for dispersion interaction and beyond in density functional theory through force matching." Journal of Chemical Physics 133, no. 17 (November 7, 2010): 174115. http://dx.doi.org/10.1063/1.3503656.

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19

Egorov, S. A., and N. H. March. "Deformation of atomic density in a homonuclear diatomic molecule due to dispersion interaction." Physics Letters A 157, no. 1 (July 1991): 57–59. http://dx.doi.org/10.1016/0375-9601(91)90408-z.

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20

Antony, Jens, and Stefan Grimme. "Fully ab initio protein-ligand interaction energies with dispersion corrected density functional theory." Journal of Computational Chemistry 33, no. 21 (May 9, 2012): 1730–39. http://dx.doi.org/10.1002/jcc.23004.

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21

Prescott, David R. C. "The effects of habitat density and the spatial distribution of food on the social behaviour of captive wintering American Tree Sparrows." Canadian Journal of Zoology 65, no. 3 (March 1, 1987): 522–26. http://dx.doi.org/10.1139/z87-081.

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Two artificial habitats containing 15% (low density) and 40% (high density) coniferous ground cover, and three feeding patterns representing different levels of spatial food distribution were used to investigate the effects of factors influencing individual spacing on the behaviour of captive, wintering American Tree Sparrows (Spizella arborea). Specifically, three aspects of social behaviour were examined: the frequency of agonistic encounters, the percentage of interactions initiated by dominants, and nearest-neighbour distances. Temperature effects were also considered. Interaction rates were lowest when food was most dispersed, and at higher temperatures. More interactions were recorded in the higher density habitat, as compared with the low density habitat, but the trend was reversed when food was highly dispersed. Nearest-neighbour distances decreased with increasing habitat density and food dispersion and were shortest in the high density habitat. Dominant birds initiated most encounters (70.7%), but less frequently when food was abundant or temperatures high, contradicting an assumption of previous models of optimal flock behaviour. It is suggested that these models, which rely on predicted changes in the allocation of available time by dominant birds to predict flock size, could be improved by considering the effects of habitat density and food dispersion, as well as differences in the social optimization strategies of different flocking species.

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22

QUANG, NGUYEN HONG, and NGUYEN MINH KHUE. "DENSITY-DEPENDENT PHONORITON STATES IN HIGHLY EXCITED SEMICONDUCTORS." International Journal of Modern Physics B 09, no. 28 (December 30, 1995): 3725–33. http://dx.doi.org/10.1142/s0217979295001488.

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The dynamical aspects of the phonoriton state in highly-photoexcited semiconductors is studied theoretically. The effect of the exciton–exciton interaction and nonbosonic character of high-density excitons are taken into account. Using Green's function method and within the Random Phase Approximation it is shown that the phonoriton dispersion and damping are very sensitive to the exciton density, characterizing the excitation degree of semiconductors.

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23

Ontaneda, Jorge, Francesc Viñes, Francesc Illas, and Ricardo Grau-Crespo. "Double-well potential energy surface in the interaction between h-BN and Ni(111)." Physical Chemistry Chemical Physics 21, no. 21 (2019): 10888–94. http://dx.doi.org/10.1039/c8cp07880g.

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Density functional theory calculations with non-local correlation functionals, properly accounting for dispersion forces, predict the presence of two minima in the interaction energy between h-BN and Ni(111).

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24

Palermo, Giovanna, Kandammathe Valiyaveedu Sreekanth, and Giuseppe Strangi. "Hyperbolic dispersion metamaterials and metasurfaces." EPJ Applied Metamaterials 7 (2020): 11. http://dx.doi.org/10.1051/epjam/2020015.

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In recent years a wide interest has been spurred by the inverse design of artificial materials for nano-biophotonic applications. In particular, the extreme optical properties of artificial hyperbolic dispersion nanomaterials allowed to access new physical effects and mechanisms. The unbound isofrequency surfaces of hyperbolic metamaterials and metasurfaces allow to access virtually infinite photonic density of states, ultrahigh confinement of electromagnetic fields and anomalous wave propagation. Here, we report the most relevant physical properties of different hyperbolic dispersion material geometries and how they allow to control light-matter interaction at the single nanometer scale, in biological matter.

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25

RIAHI, SIAVASH, SOLMAZ EYNOLLAHI, and MOHAMMAD REZA GANJALI. "INTERACTION OF EMODIN WITH DNA BASES: A DENSITY FUNCTIONAL THEORY." Journal of Theoretical and Computational Chemistry 09, no. 05 (October 2010): 875–88. http://dx.doi.org/10.1142/s0219633610006055.

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In this study, we present work on the physicochemical interaction between the anticancer drug molecule Emodin (ED) and DNA. Comprehending the physicochemical properties of this drug besides the mechanism by which it interacts with DNA should eventually permit the rational design of novel anticancer or antiviral drugs. The final purpose is the clarification of this novel class of drugs as potential pharmaceutical agents. The properties of the isolated intercalator ED and its stacking interactions with adenine⋯thymine (AT) and guanine⋯cytosine (GC) (nucleic acid base pairs) in face-to-face and face-to-back models were studied by means of the density functional tightbinding (DFTB) method. This method was an approximate version of the density functional theory (DFT) method and it includes London dispersion energy. The molecular modeling of the complex formed between ED and DNA indicated that this complex was capable of contributing to the formation of a constant intercalation site. The results exhibit that ED changes affect DNA structure with reference to bond lengths, bond angles, torsion angles, and charges.

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26

Campi, D., M. Bernasconi, G. Benedek, A. P. Graham, and J. P. Toennies. "Surface lattice dynamics and electron–phonon interaction in cesium ultra-thin films." Physical Chemistry Chemical Physics 19, no. 25 (2017): 16358–64. http://dx.doi.org/10.1039/c7cp01572k.

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The phonon dispersion curves of ultrathin films of Cs(110) on Pt(111) measured with inelastic helium atom scattering (HAS) are reported and compared with density-functional perturbation theory calculations. The mass-enhancement factor is derived from the temperature dependence of the HAS Debye–Waller exponent.

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27

Sawa, T., and M. Fujimoto. "Bisymmetric Spiral Magnetic Fields and Gravitational Instabilities of Galactic Disks." Symposium - International Astronomical Union 140 (1990): 125–26. http://dx.doi.org/10.1017/s0074180900189727.

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Linearized equations of motion are solved for the self-gravitating gaseous disk in interaction with the Lorentz force due to the bisymmetric spiral (BSS) magnetic fields. Since the pattern velocity of the BSS fields is very close to that of the spiral density wave, a nearly-resonant interaction occurs between these two waves to enhance spiral condensation of gas. The BSS fields seem to compensate the spiral density waves for their secular dispersion.

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28

Noh, Ji-Young, and Hanchul Kim. "Van der Waals interaction between P4 molecules: Density functional theory calculations with dispersion correction." Journal of the Korean Physical Society 60, no. 3 (February 2012): 410–14. http://dx.doi.org/10.3938/jkps.60.410.

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29

Mukherjee, Sanchita, Senthilkumar Kailasam, Manju Bansal, and Dhananjay Bhattacharyya. "Energy hyperspace for stacking interaction inAU/AUdinucleotide step: Dispersion-corrected density functional theory study." Biopolymers 101, no. 1 (October 25, 2013): 107–20. http://dx.doi.org/10.1002/bip.22289.

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30

Fischer, Michael. "Interaction of water with (silico)aluminophosphate zeotypes: a comparative investigation using dispersion-corrected DFT." Physical Chemistry Chemical Physics 18, no. 23 (2016): 15738–50. http://dx.doi.org/10.1039/c6cp02289h.

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The adsorption of water in six structurally different aluminophosphates and their silicoaluminophosphate analogues is investigated using dispersion-corrected density-functional theory calculations. In addition to predicting the interaction energies, the structural changes of the materials upon water adsorption are assessed.

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31

BELOSLUDOV, V. R., M. Yu. LAVRENTIEV, and S. A. SYSKIN. "LATTICE DYNAMICS OF YBa2Cu3O7 IN THE IONIC MODEL." International Journal of Modern Physics B 03, no. 04 (April 1989): 611–15. http://dx.doi.org/10.1142/s0217979289000452.

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A simple model of interatomic interactions in YBa 2 Cu 3 O 7, which takes into account long-range Coulombic interaction and short-range repulsion of the Born-Mayer type, is presented. On the basis of this model the calculation of lattice vibrations in YBa 2 Cu 3 O 7 is performed, and phonon dispersion curves and density of phonon states are found. A comparison with experimental data on IR and Raman spectra is presented.

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32

Arya, Balwant Singh, Mahendra Aynyas, and Sankar P. Sanyal. "Phonon Properties of Americium Sulphide." Journal of Metastable and Nanocrystalline Materials 28 (December 2016): 125–28. http://dx.doi.org/10.4028/www.scientific.net/jmnm.28.125.

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We have reported the phonon properties of AmS by using breathing shell models (BSM) which includes breathing motion of electrons of the Am atoms due to f-d hybridization. The phonon dispersion curves, density of states and specific heat calculated from present model. The calculated phonon dispersion curves of AmS are presented follow the same trend as observed in uranium sulphide. We have discussed the significance of this approach in predicting the phonon dispersion curves of this compound and examine the role of electron-phonon interaction.

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33

Liang, Zhiling, Houhe Liu, Nianjun Su, Dandan Song, Yun Zhang, Hong Huang, Jianqi Zheng, Cheng Zhong, and Guodong Ye. "Study of the Deformation/Interaction Model: How Interactions Increase the Reaction Barrier." Journal of Chemistry 2018 (2018): 1–8. http://dx.doi.org/10.1155/2018/3106297.

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The interactions (including weak interactions) between dienophiles and dienes play an important role in the Diels-Alder reaction. To elucidate the influence of these interactions on the reactivity, a popular DFT functional and a variational DFT functional corrected with dispersion terms are used to investigate different substituent groups incorporated on the dienophiles and dienes. The bond order is used to track the trajectory of the cycloaddition reaction. The deformation/interaction model is used to obtain the interaction energy from the reactant complex to the inflection point until reaching the saddle point. The interaction energy initially increases with a decrease in the interatomic distance, reaching a maximum value, but then decreases when the dienophiles and dienes come closer. Reduced density gradient and chemical energy component analysis are used to analyse the interaction. Traditional transition state theory and variational transition state theory are used to obtain the reaction rates. The influence of tunneling on the reaction rate is also discussed.

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34

Stein, Frederick, Jürg Hutter, and Vladimir V. Rybkin. "Double-Hybrid DFT Functionals for the Condensed Phase: Gaussian and Plane Waves Implementation and Evaluation." Molecules 25, no. 21 (November 6, 2020): 5174. http://dx.doi.org/10.3390/molecules25215174.

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Intermolecular interactions play an important role for the understanding of catalysis, biochemistry and pharmacy. Double-hybrid density functionals (DHDFs) combine the proper treatment of short-range interactions of common density functionals with the correct description of long-range interactions of wave-function correlation methods. Up to now, there are only a few benchmark studies available examining the performance of DHDFs in condensed phase. We studied the performance of a small but diverse selection of DHDFs implemented within Gaussian and plane waves formalism on cohesive energies of four representative dispersion interaction dominated crystal structures. We found that the PWRB95 and ωB97X-2 functionals provide an excellent description of long-ranged interactions in solids. In addition, we identified numerical issues due to the extreme grid dependence of the underlying density functional for PWRB95. The basis set superposition error (BSSE) and convergence with respect to the super cell size are discussed for two different large basis sets.

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35

Detmar, Eric, Valentin Müller, Daniel Zell, Lutz Ackermann, and Martin Breugst. "Cobalt-catalyzed C–H cyanations: Insights into the reaction mechanism and the role of London dispersion." Beilstein Journal of Organic Chemistry 14 (June 25, 2018): 1537–45. http://dx.doi.org/10.3762/bjoc.14.130.

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Carboxylate-assisted cobalt(III)-catalyzed C–H cyanations are highly efficient processes for the synthesis of (hetero)aromatic nitriles. We have now analyzed the cyanation of differently substituted 2-phenylpyridines in detail computationally by density functional theory and also experimentally. Based on our investigations, we propose a plausible reaction mechanism for this transformation that is in line with the experimental observations. Additional calculations, including NCIPLOT, dispersion interaction densities, and local energy decomposition analysis, for the model cyanation of 2-phenylpyridine furthermore highlight that London dispersion is an important factor that enables this challenging C–H transformation. Nonbonding interactions between the Cp* ligand and aromatic and C–H-rich fragments of other ligands at the cobalt center significantly contribute to a stabilization of cobalt intermediates and transition states.

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36

Proynov, Emil, Fenglai Liu, Zhengting Gan, Matthew Wang, and Jing Kong. "Density-functional approach to the three-body dispersion interaction based on the exchange dipole moment." Journal of Chemical Physics 143, no. 8 (August 28, 2015): 084125. http://dx.doi.org/10.1063/1.4929581.

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37

Krishtal, Alisa, Kenno Vanommeslaeghe, András Olasz, Tamás Veszprémi, Christian Van Alsenoy, and Paul Geerlings. "Accurate interaction energies at density functional theory level by means of an efficient dispersion correction." Journal of Chemical Physics 130, no. 17 (May 7, 2009): 174101. http://dx.doi.org/10.1063/1.3126248.

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38

DiLabio, Gino A., Erin R. Johnson, and Alberto Otero-de-la-Roza. "Performance of conventional and dispersion-corrected density-functional theory methods for hydrogen bonding interaction energies." Physical Chemistry Chemical Physics 15, no. 31 (2013): 12821. http://dx.doi.org/10.1039/c3cp51559a.

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39

Mandal, Swapan. "Effects of Field-Induced Coherence on Laser Without Population Inversion and on Absorptionless Dispersion for a V-Type Three Level System." International Journal of Modern Physics B 17, no. 14 (June 10, 2003): 2715–33. http://dx.doi.org/10.1142/s0217979203018363.

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A V-type three level system with two closely spaced upper levels interacting with a single mode of the electromagnetic field is studied for the absorptive and dispersive lineshapes. A semiclassical description for the atom-field interaction is being adopted to obtain the usual optical Bloch equations. The approximate analytical solutions for the density matrix elements are obtained by solving coupled optical Bloch equations. Through the off-diagonal density matrix elements, the introduction of phase angles between the levels participating in dipole allowed transitions are automatic. It is shown that these phases are appreciable if the applied electromagnetic field is strong. These field dependent phases (coherence) are responsible for the reduction of the inversionless gain and the absorptionless dispersion. For large decay constants, it is found that the energy gap between the upper two levels has no role to play on the laser without inversion and on the absorptionless dispersion. However, for large population per unit decay, a significant increase of the absorptionless dispersion and the inversionless gain is obtained. The condition for large population decay and a possible experimental realization of the field dependent phases are discussed.

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40

Ghosh, S., and Apurva Muley. "Acousto–electric interaction in inhomogeneous semiconductor quantum plasma." International Journal of Modern Physics B 31, no. 28 (November 9, 2017): 1750207. http://dx.doi.org/10.1142/s0217979217502071.

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In the present paper, an analytical study has been presented to examine the acousto–electric interactions in piezoelectric inhomogeneous semiconductor quantum plasma. The analysis is made by deriving the quantum-modified dispersion relation and subsequently deducing the expression of gain coefficient of acoustic wave using quantum hydrodynamic (QHD) model for inhomogeneous semiconductor plasma. The linearly and quadratically varying plasma density profiles have been chosen to investigate the effects of inhomogeneity through density gradient. We address the role of quantum parameter-H, scale length of density variation L and propagation distance z on gain profiles of acoustic wave. It has been found that the presence of these parameters can significantly modify the crossover and resonance characteristics of acoustic wave. Results reveal that the crossover point for wave amplification is found to be greater than unity in inhomogeneous quantum plasma media while the resonance condition is effectively influenced by these parameters in all the considered cases. We found that more acoustic gain would be possible if the acoustic mode propagates from low to high plasma density region in the medium. It is also found that as the medium tends to have high inhomogeneity, more pronounced modifications on resonance characteristics of acoustic wave are expected.

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41

Sangameswaran, B., and M. Gomathi. "Enhancement of dissolution rate of Olmesartan medoxomil using urea as carrier by different solid dispersion techniques." International Journal of Research in Pharmaceutical Sciences and Technology 1, no. 1 (November 14, 2018): 36–42. http://dx.doi.org/10.33974/ijrpst.v1i1.35.

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The poor solubility of drug substances in water and their low dissolution rate in aqueous G.I.T fluid often leads to insufficient bioavailability. As per Biopharmaceutical Classification System (BCS), Olmesartan belongs to the class-II category having poor solubility and high permeability. Since only dissolved drug can pass the gastrointestinal membrane, the proper solubility of the drug is ultimately desired. Its oral bioavailability is 26%. Hence, an attempt was made to enhance its solubility by formulating solid dispersions using different techniques viz., Melting, Kneading, Co-precipitation, Solvent evaporation and Physical mixing etc., Drug and carrier (Urea) in different ratios like 1: 1, 1: 2, 1: 3 and 1:4 were used for formulating solid dispersions. The compatibility of the drug with the carrier was checked by FTIR studies, these results revealed that there was no interaction between them. The angle of repose, bulk density, tapped density; Carr’s index and Hausner ratio were calculated for the micrometric characterization of all the solid dispersions. The drug content was found to be high and uniform in all formulations. The prepared Solid dispersion SEM4 (1:4) showed minimal wetting time of 13 seconds compared with the other formulations. In vitro dissolution, release studies in Phosphate buffer pH of 6.8 revealed that the prepared solid dispersions showed faster drug release compared with the pure drug. The in vitro dissolution profile showed ascendency on increasing the carrier concentration

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42

Dey, Ram Chandra, Prasenjit Seal, and Swapan Chakrabarti. "CH/π Interaction in Benzene and Substituted Derivatives with Halomethane: A Combined Density Functional and Dispersion-Corrected Density Functional Study." Journal of Physical Chemistry A 113, no. 37 (September 17, 2009): 10113–18. http://dx.doi.org/10.1021/jp905078p.

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43

West, J. R., I. Guymer, Y. Sangodoyin, and K. O. K. Oduyemi. "Solute Dispersion and Sediment Transport in Estuaries." Water Science and Technology 18, no. 4-5 (April 1, 1986): 93–100. http://dx.doi.org/10.2166/wst.1986.0184.

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Synoptic measurements of velocity and salinity at several points on up to five vertical profiles at a cross-section in the Conwy show that solute dispersion coefficients are affected by secondary flow induced by the interaction of transverse shear and the salinity induced longitudinal density gradient. It is concluded that dispersion coefficients are temporally and spatially dependent and a simple empirical formula is suggested. Some data from the initial stages of a similar study of sediment transport show that techniques exist which permit the study of the turbulent fluctuations of suspended solids concentration and the evaluation of the tidal dependence of suspended solids transport phenomena.

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44

Murashkevich, A. N. "Interaction of titanium oxide with sodium hydroxide at hydrothermal conditions." Proceedings of the National Academy of Sciences of Belarus, Chemical Series 56, no. 2 (June 7, 2020): 150–57. http://dx.doi.org/10.29235/1561-8331-2020-56-2-150-157.

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Sodium titanates were obtained by hydrothermal treatment using titanium tetrabutoxide (ТBT), titanium tetroisopropoxide (TIPT), hydrated titanium dioxide (prepared by hydrolysis of titanium alkoxide) or air-dried TiO2 sol with a molar ratio of TBT/TIPT/TiO2: NaOH equal to 1:10–80, at the temperature 130–180 °C and treatment time 24–72 h. Samples were characterized by the adsorption method, X-ray phase analysis, scanning electron microscopy. The photocatalytic properties of nanostructured titanate in the H-form in the process of Rhodamine FL–BM photodegradation under UV-irradiation (K = 0.03–0.05 min–1), as well as the electrorheological properties, were evaluated. Partially hydrated sodium titanates as a filler of the electrorheological dispersion (the filler content of dispersion was 5 %) exhibited the shear stress of 50–60 Pa and the leakage current density of 1.0–1.5 μA/cm2 at an electric field strength of E = 4 kV/cm at a shear rate of 17.1 s–1.

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SHUKLA, P. K., and L. STENFLO. "Dispersion relations for electromagnetic waves in a dense magnetized plasma." Journal of Plasma Physics 74, no. 6 (December 2008): 719–23. http://dx.doi.org/10.1017/s0022377808007344.

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AbstractDispersion relations for elliptically polarized extraordinary as well as linearly polarized ordinary electromagnetic waves propagating across an external magnetic field in a dense magnetoplasma are derived, taking into account the combined effects of the quantum electrodynamical (QED) field, as well as the quantum forces associated with the Bohm potential and the magnetization energy of the electrons due to the electron-1/2 spin effect. The QED (vacuum polarization) effects, which contribute to the nonlinear electron current density, modify the refractive index. Our results concern the propagation characteristics of perpendicularly propagating high-frequency electromagnetic waves in dense astrophysical objects (e.g. neutron stars and magnetars), as well as the next-generation intense laser–solid density plasma interaction experiments and quantum free-electron laser schemes.

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Tao, Yaping, Ligang Han, Andong Sun, Kexi Sun, Qian Zhang, Wanqiang Liu, Jianbin Du, and Zhaojun Liu. "Crystal Structure and Computational Study on Methyl-3-Aminothiophene-2-Carboxylate." Crystals 10, no. 1 (January 1, 2020): 19. http://dx.doi.org/10.3390/cryst10010019.

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Methyl-3-aminothiophene-2-carboxylate (matc) is a key intermediate in organic synthesis, medicine, dyes, and pesticides. Single crystal X-ray diffraction analysis reveals that matc crystallizes in the monoclinic crystal system P21/c space group. Three matc molecules in the symmetric unit are crystallographically different and further linked through the N–H⋯O and N–H⋯N hydrogen bond interactions along with weak C–H⋯S and C–H⋯Cg interactions, which is verified by the three-dimensional Hirshfeld surface, two-dimensional fingerprint plot, and reduced density gradient (RDG) analysis. The interaction energies within crystal packing are visualized through dispersion, electrostatic, and total energies using three-dimensional energy-framework analyses. The dispersion energy dominates in crystal packing. To better understand the properties of matc, electrostatic potential (ESP) and frontier molecular orbitals (FMO) were also calculated and discussed. Experimental and calculation results suggested that amino and carboxyl groups can participate in various inter- and intra-interactions.

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47

Esrafili, Mehdi D., and Mohammad Solimannejad. "On the strength and nature of intermolecular X···O interactions in CF2ClBr−O3 complexes (X = F, Cl, Br): an ab initio investigation." Canadian Journal of Chemistry 92, no. 1 (January 2014): 33–39. http://dx.doi.org/10.1139/cjc-2013-0372.

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Ab initio calculations were realized to analyze the existence of intermolecular X···O interactions in bromochlorodifluoromethane (CF2ClBr) complexes with ozone, where X = F, Cl, and Br. These calculations have been carried out using MP2 and CCSD(T) methods, through analysis of surface electrostatic potentials V(r), intermolecular interaction energies, and electron density analysis. Coupled cluster (CCSD(T)/aug-cc-pVTZ//MP2/aug-cc-pVTZ) calculations indicate that the stabilization energies for the CF2ClBr−O3 complexes lie in the range between –3.9 and –7.7 kJ/mol. The characteristic of X···O interactions has been identified in terms of the electron density analysis within the quantum theory of atoms in molecules. Energy decomposition analysis shows that the attractive nature of the X···O interactions within the title complexes is chiefly due to dispersion effects, but electrostatic contribution also plays an important role.

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Rossi Fernández, Ana C., Nicolás F. Domancich, Ricardo M. Ferullo, and Norberto J. Castellani. "Aluminum adsorption on graphene: Theoretical study of dispersion effects." Journal of Theoretical and Computational Chemistry 18, no. 04 (June 2019): 1950019. http://dx.doi.org/10.1142/s0219633619500196.

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The interaction between a single atom and graphene is an example in which the density functional theory (DFT) presents serious difficulties in giving an appropriate description of the adsorbate–substrate interaction, giving also different predictions according to the chosen approximation. The present calculations sustain that the inclusion of dispersion interactions in the framework of DFT for the Al/graphene system lead to potential energy curves of different nature according to the theoretical approach employed. The adsorption of an Al atom on the graphene surface was studied using both cluster and slab models. Cluster DFT–PBE calculations show the presence of a minimum at hollow site at an Al–graphene distance of about 2.1–2.3 Å corresponding to an exothermic state. Conversely, under B3LYP the same adsorption mode is endothermic. In comparison, our MP2 reference calculations predict the formation of two minima, both of exothermic nature, separated by an important energy barrier (about 0.2–0.4[Formula: see text]eV). The incorporation of empirical van der Walls (vdW) corrections to B3LYP changes the original behavior, giving an exothermic adsorption; furthermore, it produces a second, more external minimum. Slab calculations with PBE, and specially using the vdW-DF2 functional, predict also the formation of a minimum of very low depth at about 3.1 Å. The analysis of results obtained with cluster and slab models sustains that the bonding of the inner minima is of ionic character while that of the external ones is of dispersion character.

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Wu, Chen-Huan. "Two-dimensional parabolic Dirac system in the presence of nonmagnetic and magnetic impurities." International Journal of Modern Physics B 35, no. 12 (May 10, 2021): 2150159. http://dx.doi.org/10.1142/s0217979221501599.

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We theoretically investigate the effect of the nonmagnetic and magnetic impurities to the 2D parabolic Dirac system. The induced charge density by the charged impurity is obtained by the linear response theory within the random phase approximation. We also calculate in-detail, the Ruderman–Kittel–Kasuya–Yosida (RKKY) interaction between two magnetic impurities placed within the 2D sheet of the Dirac materials with isotropic and anisotropic dispersion. For the anisotropic dispersion, the RKKY interaction is also anisotropic and related to the lattice parameters which can be obtained through the DFT calculation or the experiments. The features of the RKKY interaction also can be treated as a signature of the topological phase transition as well as the change of Berry curvature. Our results are also illuminating to the study of the static screening and the RKKY interaction of the isotropic or anisotropic 3D Dirac/Weyl semimetals or the 2D transition metal dichalcogenide family.

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Eremin, Roman, Pavel Zolotarev, and Ivan Bobrikov. "Delithiated states of layered cathode materials: doping and dispersion interaction effects on the structure." EPJ Web of Conferences 177 (2018): 02001. http://dx.doi.org/10.1051/epjconf/201817702001.

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Here we present results of density functional theory (DFT) study of delithiated structures of layered LiNiO2 (LNO, Li12Ni12O24 model) cathode material and its doped analogue LiNi0.833Co0.083Al0.083O2 (N10C1A1, Li12Ni10CoAlO24 model). The paper is aimed at independent elucidation of doping and dispersion interaction effects on the structural stability of cathode materials studied. For this purpose, the LNO and N10C1A1 configurational spaces consisting of 87 and 4512 crystallographically independent configurations (obtained starting from 2×2×1 supercell of R-3m structure of LNO) are optimized within a number of DFT models. Based on a comparison of the calculated dependencies for the lattice parameters with the results of in situ neutron diffraction experiments, the most pronounced effect of cathode material stabilization is due to the dispersion interaction. In turn, the doping effect is found to affect cathode structure behavior at the latest stages of delithiation only.

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