Theoretical analysis of ammoniaborane and alkylammoniaborane at the solid state

2017 ◽  
Author(s):  
Mariano Méndez Chávez
Keyword(s):  
Density Functional Theory ◽  
Solid State ◽  
Theoretical Analysis ◽  
Gas Phase ◽  
Density Functional ◽  
Structural Parameters ◽  
Ammonia Borane ◽  
Functional Theory ◽  
The Density Functional Theory

This work deals with a benchmark for the calculation of the structural parameters of ammonia-borane and alkylammonia-borane at the solid state, using hybrid and GGA functionals in the framework of the Density Functional Theory as well as the use of Grimme's empirical dispersion. A comparison for some dimers of the aforementioned species, calculated at the gas-phase at the level MP2/aug-cc-pVTZ is discussed.

Theoretical analysis of ammoniaborane and alkylammoniaborane at the solid state

2017 ◽  
Author(s):  
Mariano Mendez Chavez
Keyword(s):  
Density Functional Theory ◽  
Solid State ◽  
Theoretical Analysis ◽  
Gas Phase ◽  
Density Functional ◽  
Structural Parameters ◽  
Ammonia Borane ◽  
Functional Theory ◽  
The Density Functional Theory

This work deals with a benchmark for the calculation of the structural parameters of ammonia-borane and alkylammonia-borane at the solid state, using hybrid and GGA functionals in the framework of the Density Functional Theory as well as the use of Grimme's empirical dispersion. A comparison for some dimers of the aforementioned species, calculated at the gas-phase at the level MP2/aug-cc-pVTZ is discussed.

The impact of cation–π, anion–π, and CH–π interactions on the excited-state intramolecular proton transfer of 1,4-dihydroxyanthraquinone

2021 ◽  
Author(s):  
Asiyeh Shahraki ◽  
Ali Ebrahimi ◽  
Shiva Rezazadeh ◽  
Roya Behazin
Keyword(s):  
Density Functional Theory ◽  
Gas Phase ◽  
Density Functional ◽  
Photophysical Properties ◽  
Intramolecular Proton Transfer ◽  
Time Dependent ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
The Impact ◽  
Dependent Density

The impact of ion-π interactions on the photophysical properties of quinizarin have been investigated using the density functional theory and time-dependent density functional theory at the M06-2X/6-311++G(d,p) level in the gas phase and solution.

scholarly journals Cerium-Doped Endohedral Fullerene: A Density-Functional Theory Study

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
A. Z. AlZahrani
Keyword(s):  
Density Functional Theory ◽  
Total Energy ◽  
Density Functional ◽  
Structural Parameters ◽  
Repulsive Interaction ◽  
Total Density ◽  
Generalized Gradient ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Structural And Electronic Properties

First-principles total energy calculations of the structural and electronic properties of Ce-doped fullerene have been performed within the framework of the density functional theory at the generalized gradient approximation level. Among various locations, Ce atom was found to engage with the six-fold carbon ring. The total energy is found to significantly change as the Ce atom being shifted from the center of the cage toward the edge close to the six-membered ring where the total energy reaches its local minimum. Moreover, repulsive interaction between Ce atom and the cage components turns as the adatom directly interacts with the six C atoms of the ring. The lowest-energy CeC60 geometry is found to have a binding energy of approximately 5.34 eV, suggesting strong interaction of the dopant with the cage members. Furthermore, fundamental key structural parameters and the total density of states of the optimized structure have been determined and compared with the available data.

Structure Study of ZnO:Eu with the Supercell Method

2010 ◽  
Vol 9 ◽  
pp. 25-30 ◽  
Author(s):  
A. Blanca-Romero ◽  
A. Flores-Riveros ◽  
J.F. Rivas-Silva
Keyword(s):  
Density Functional Theory ◽  
Rare Earth ◽  
Solid State ◽  
Density Functional ◽  
Cell Model ◽  
Structure Study ◽  
Functional Theory ◽  
Kondo Resonance ◽  
Super Cell ◽  
The Density Functional Theory

One of the interests on the study of doped materials with rare earths in their bulk or nanoscale size is owing to the enhancement of the intensity of light in their photoluminescence when a lanthanide exists in a receptor material, as ZnO in our case. Until now, one of the most useful theories for calculations of electronic properties in molecular and solid state systems is the Density Functional Theory (DFT), which is not capable to manage well the presence of high localized electrons, as in lanthanide compounds in general and the doped case in particular. We propose to study these materials with super cell model using some correction to the standard calculations. For this goal, we employ the WIEN2k [1] code using the LDA+U approximation to take into account the strong correlation of the f electrons coming from the lanthanide. We emphasise the study of deformation due to the presence of Eu ion in the structure of host material, optimizing the position of neighboring Oxygen atoms. This deformation has been related to Kondo Resonance [2] appearing around the Fermi Energy of the compound, due to hybridization [3] among the f electrons from rare earth and neighboring oxygen levels.

The Structure of Two 1-(Nitrophenyl)-Δ2-pyrazolines: a Crystallographic and Theoretical Study

2004 ◽  
Vol 57 (11) ◽  
pp. 1103 ◽  
Author(s):  
Glenn P. A. Yap ◽  
Ibon Alkorta ◽  
Nadine Jagerovic ◽  
José Elguero
Keyword(s):  
Density Functional Theory ◽  
Solid State ◽  
Gas Phase ◽  
Density Functional ◽  
Theoretical Study ◽  
Chemical Shifts ◽  
Molecular Structures ◽  
Steric Effects ◽  
Functional Theory ◽  
Crystal And Molecular Structures

The crystal and molecular structures of two nitrophenylpyrazolines have been determined. The geometries have been used as starting geometries for density functional theory (DFT) calculations. The differences in conformation between both molecules and between the solid state and gas phase are explained in terms of steric effects. An attractive intramolecular N···N interaction between the nitro group and the pyrazoline N2 nitrogens has been found. Absolute shieldings have been calculated (GIAO) and compared with experimental 1H and 13C chemical shifts.

cis-[(η5-C5H5)Fe(η1-CO)(μ-CO)]2, the poor relative between cis and trans tautomers. A theoretical study of the gas-phase Fe L3-edge and C and O K-edge XAS of trans-/cis-[(η5-C5H5)Fe(η1-CO)(μ-CO)]2.

2021 ◽  
Author(s):  
Silvia Carlotto ◽  
Girolamo Casella ◽  
Mauro Sambi ◽  
Maurizio Casarin
Keyword(s):  
Density Functional Theory ◽  
Gas Phase ◽  
Relative Stability ◽  
Density Functional ◽  
Theoretical Study ◽  
Dielectric Constants ◽  
Functional Theory ◽  
The Poor ◽  
The Density Functional Theory ◽  
Cis And Trans

The relative stability of trans-[(η5-C5H5)Fe(η1-CO)(μ-CO)]2 (trans-I) and cis-I tautomers in vacuum and in solvents with different dielectric constants (ε) has been investigated by exploiting the density functional theory (DFT). Theoretical...

scholarly journals HEAT OF HYDRATION OF DIETHYLSULFONE BY QUANTUM CHEMICAL CALCULATION

2018 ◽  
Vol 61 (8) ◽  
pp. 17
Author(s):  
Ashot S. Mkhitaryan ◽  
Zakar K. Papanyan ◽  
Liana S. Gabrielyan ◽  
Shiraz A. Markarian
Keyword(s):  
Density Functional Theory ◽  
Potential Energy ◽  
Potential Energy Surface ◽  
Gas Phase ◽  
Quantum Chemical ◽  
Density Functional ◽  
Energy Surface ◽  
Average Energy ◽  
Functional Theory ◽  
The Density Functional Theory

The quantum chemical study of the hydration of diethyl sulfone was performed by using Gaussian 09 software package. The conformational analysis of the isolated molecule of diethyl sulfone is performed by the restricted Hartree-Fock (RHF) and the density functional theory (DFT/B3PW91) methods with 6-311++G(d,p) extended basis set. The analysis of the potential energy surface revealed the existence of four stable conformers of diethyl sulfone with different degrees of degeneracy. The nature of stationary points on the potential energy surface is verified by the complete gas phase optimization and the vibrational analysis. The global minimum is the conformer with two (CCSC) dihedral angles equal 180°. The fractional population distribution of different conformers is determined by Boltzmann distribution. The average energy of the diethyl sulfone molecule in vacuum is calculated. To account the effect of solvent the self-consistent reaction field (SCRF) method, particularly, solvent model based on electron density (SMD), was employed. It is shown, that solvent affects on the relative population of conformers. The thermodynamic parameters, in particular enthalpy, for the conformers of diethyl sulfone are determined both in the gas phase and in the aqueous solution. The average energy of diethyl sulfone in water is calculated. It is shown, that although the dissolution of crystalline diethyl sulfone in water is an endothermic process, the hydration of diethyl sulfone molecules occurs with the release of heat. The heat of dissolution of diethyl sulfone calculated by the density functional theory is consistent with the experimental data.

Structure and Properties of Diamond-Like Phases

2016 ◽  
Vol 845 ◽  
pp. 231-234 ◽  
Author(s):  
Vladimir Greshnyakov ◽  
Evgeniy A. Belenkov
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Structural Parameters ◽  
Three Dimensional ◽  
Density Functional Theory Method ◽  
Theory Method ◽  
Structure And Properties ◽  
Functional Theory ◽  
Graphene Layers ◽  
The Density Functional Theory

The geometrically optimized structures of twenty three carbon diamond-like phases obtained by linking graphene layers, carbon nanotubes, and three-dimensional graphites has been calculated using the density functional theory method and the structural parameters, densities, sublimation energies, electronic properties, and bulk moduli have been calculated.

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