Wechselwirkungen in Molekülkristallen, 166 [1, 2]. Polyiod-Moleküle I2C=CI2, (IC)4S, (IC)4NH, (IC)4N-CH3 und HCI3: Strukturbestimmung nach Kristallzüchtung oder durch Dichtefunktionaltheorie-Berechnung / Interaction in Molecular Crystals, 166 [1, 2], Polyiodo Molecules I2C=CI2, (IC)4S, (IC)4 NH, (IC)4N-CH and HCI3: Structure Determination Following Crystallization or by Density Functional Theory Calculation

2001 ◽  
Vol 56 (1) ◽  
pp. 13-24 ◽  
Author(s):  
Hans Bock ◽  
Sven Holl ◽  
Volker Krenzel
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Crystal Packing ◽  
Density Functional Theory Calculation ◽  
Density Functional Theory Calculations ◽  
Structural Data ◽  
Basis Sets ◽  
Functional Theory ◽  
Donor Acceptor ◽  
Density Functional Theory Optimization

Abstract The structures of tri-and tetraiodo-substituted carbon compounds are determined either expe­rimentally by X-Ray Structure Analysis or, because crystallization of tetraiodothiophene could not be achieved, approximated by Density Functional Theory optimization of structural data from a donor/acceptor complex. The structures show noteworthy details such as a second po­lymorph of tetraiodoethene crystallized by sublimation or herringbone crystal packing patterns of tetraiodopyrrole derivatives. All molecular geometries are discussed and compared based on relativistic density functional theory calculations with 6 -31G* basis sets including iodine pseudopotentials. They reproduce even finer structural details due to van der Waals repulsion of the bulky iodo substituents. Natural Bond Orbital (NBO) charge distributions suggest positive partial charges at all iodine centers with the strongest polarization Cδ㊀ → Iδ㊉ in HCI3, which contains well over 97% iodine.

Potential thermally activated delayed fluorescence properties of a series of 2,3-dicyanopyrazine based compounds

2018 ◽  
Vol 3 (7) ◽  
Author(s):  
Ayşegül Gümüş ◽  
Selçuk Gümüş
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Delayed Fluorescence ◽  
Basis Sets ◽  
Functional Theory ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Structural And Electronic Properties ◽  
Donor Acceptor ◽  
Almost All

Abstract 2,3-Dicyanopyrazine based acceptor was combined with a series of well studied donors to obtain donor-acceptor type potential thermally activated delayed fluorescence emitters. Their structural and electronic properties were computed theoretically at the level of density functional theory and time dependent density functional theory with the application of two different hybrid functionals and various basis sets. Almost all of the designed structures were computed to have the potential of being TADF compounds since they possess very narrow singlet-triplet gaps. Indeed, acridine-pyrazine (9) derivative was calculated to be the best candidate for the purpose among them.

Fast computation of DFT nuclear gradient with multiresolution*This article is dedicated to Dr. Russell J. Boyd for his distinguished career in chemical research.

2011 ◽  
Vol 89 (6) ◽  
pp. 657-662 ◽  
Author(s):  
Nicholas J. Russ ◽  
Chun-min Chang ◽  
Jing Kong
Keyword(s):  
Density Functional Theory ◽  
Electron Density ◽  
Density Functional ◽  
Density Functional Theory Calculation ◽  
Computational Cost ◽  
Basis Sets ◽  
Local Spin Density Approximation ◽  
Functional Theory ◽  
Exchange Correlation ◽  
The Impact

We present an efficient algorithm for evaluating the exchange-correlation contribution to the nuclear gradients of density-functional theory calculation within the local spin-density approximation. The algorithm is an extension of the multiresolution exchange-correlation (mrXC) method, which treats smooth and compact parts of the electron density separately. The nuclear gradient of the smooth density is calculated on the even-spaced grid while the compact part of the density is handled on the normal atom-centered grid (ACG). The overall formulism is still formally based on the ACG, and thus does not change the results of the existing ACG-based algorithms for all-electron density-functional theory (DFT) calculations. The variation of the positions and weights of ACG owing to the nuclear perturbation is also handled rigorously. Benchmark calculations with different basis sets and sizes of ACG show that mrXC reduces the computational cost by several times without loss of accuracy. It also lessens the impact on the CPU time when the size of the ACG is increased.

Molecular structure and tautomers of [30]trithia-2,3,5,10,12,13,15,20,22,23,25,30-dodecaazahexaphyrin

2013 ◽  
Vol 17 (03) ◽  
pp. 220-228 ◽  
Author(s):  
Yuriy A. Zhabanov ◽  
Alexander V. Zakharov ◽  
Sergei A. Shlykov ◽  
Olga N. Trukhina ◽  
Elena A. Danilova ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Density Functional Theory ◽  
Gas Phase ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Equilibrium Structure ◽  
Mass Spectrometric ◽  
Basis Sets ◽  
Functional Theory ◽  
Mass Spectrometric Experiment

The gas-phase molecular structure of the unsubstituted [30]trithia-2,3,5,10,12,13,15,20,22,23,25,30-dodecaazahexaphyrin (C30H15N15S3) has been studied by a synchronous gas electron diffraction and mass spectrometric experiment and density functional theory calculations using the B3LYP hybrid method and cc-pVTZ basis sets. The molecule has an equilibrium structure of D 3h symmetry with a planar macrocycle and the thiadiazole rings oriented in such a way that the sulfur atoms point outwards from the inner cavity. Tautomers of this compound have been studied by DFT computations.

Basis Set Effects in Density Functional Theory Calculation of Muoniated Cytosine Nucleobase

2020 ◽  
Vol 860 ◽  
pp. 282-287
Author(s):  
Wan Nurfadhilah Zaharim ◽  
Shukri Sulaiman ◽  
Saidah Sakinah Mohd Tajudin ◽  
Siti Nuramira Abu Bakar ◽  
Nur Eliana Ismail ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Total Energy ◽  
Density Functional ◽  
Density Functional Theory Calculation ◽  
Geometry Optimization ◽  
Density Functional Theory Method ◽  
Basis Set ◽  
Basis Sets ◽  
Functional Theory ◽  
Muonium Hyperfine

The Density Functional Theory method was employed to investigate the electronic structure and muonium hyperfine interaction of muonium trapped near carbon atom labelled as '5' in cytosine nucleobase. Eighteen different basis sets in combination with B3LYP functional were examined in geometry optimization calculations on the muoniated radical. There are significant quantitative differences in the calculated total energy. The employment of basis set that does not include polarization function produces an optimized structure with high total energy. The 6-311++G(d,p) basis set yielded the lowest total energy as compared to other basis sets. The bond order of muonium trapped at C5 atom is in the range of 0.841 to 0.862. The 6-31G basis set produced the muonium Fermi contact coupling constant that is the closest to the experimental value.

An X-shaped cyano–carbonyl interaction on the polar surface of (cyanoacetyl)hydrazones

CrystEngComm ◽  
2020 ◽  
Vol 22 (19) ◽  
pp. 3274-3278
Author(s):  
Zhenfeng Zhang
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Crystal Packing ◽  
Critical Role ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Polar Surface ◽  
Molecule Conformation

An X-shaped CN⋯CO interaction, which plays a critical role in dictating the molecule conformation and crystal packing patterns, has been found to occur on the polar surface of (cyanoacetyl)hydrazones, and is rationalized by density functional theory calculations.

Dissymmetric Bay-Functionalized Perylenediimides

Synlett ◽  
2018 ◽  
Vol 29 (13) ◽  
pp. 1693-1699 ◽  
Author(s):  
Prabhpreet Singh ◽  
Kapil Kumar ◽  
Gaurav Bhargava ◽  
Subodh Kumar
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Energy Gap ◽  
Twist Angle ◽  
Density Functional Theory Calculations ◽  
Two Dimensional ◽  
Functional Theory ◽  
Donor Acceptor ◽  
Homo And Lumo ◽  
Transfer Properties

We report the synthesis of perylenediimide (PDI)-based ­donor–acceptor hybrids through dissymmetric bay functionalization of PDIs. The dissymmetric bay-functionalized di- and trisubstituted PDIs were characterized by using one- and two-dimensional NMR spectroscopy. Density functional theory calculations revealed (i) an energy gap between the HOMO and LUMO in the range 2.14–2.34 eV, beneficial for charge-transfer properties; and (ii) a twist angle between the two naphthalene units in the range 17–26°, which might be beneficial for disruption of co-facial stacking of the PDI.

Sign in / Sign up

Export Citation Format

Share Document