scholarly journals Vibrational frequency analysis of CH3Cl molecule; ab initio study

2015 ◽  
Vol 5 ◽  
pp. 142-145
Author(s):  
Shiba Subedi ◽  
Jeevan Jyoti Nakarmi
Keyword(s):  
First Principles ◽  
Vibrational Frequency ◽  
Chemical Reactivity ◽  
Basis Set ◽  
Isotopic Substitution ◽  
First Principles Calculations ◽  
Bonding Analysis ◽  
The Stability ◽  
Homo Lumo ◽  
Cl Atom

First-principles calculations implemented by Gaussian 09 sets of programs has been performed in order to study the stability, electronic properties, nature of bonding and vibrational frequency assignments for CH3Cl molecule using QCISD levels of approximation with the choice of basis set 6-31G(d, p). Quantum Theory of Atoms In Molecule (QTAIM) approach has been adopted for bonding analysis and HOMO, LUMO energies were taken as the central aspects for discussing the chemical reactivity of the studied system. The vibrational frequency shift due to isotopic substitution of C-atom and Cl-atom in title molecule has been discussed. The Himalayan Physics Year 5, Vol. 5, Kartik 2071 (Nov 2014)Page: 142-145

First Principles Calculations of Double Metal Amidoboranes

2016 ◽  
Vol 852 ◽  
pp. 792-798
Author(s):  
Yang Wang ◽  
Qiang Wang
Keyword(s):  
Crystal Structures ◽  
First Principles ◽  
Density Functional ◽  
Chemical Reactivity ◽  
Frontier Molecular Orbital ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Density Distributions ◽  
Energy Gaps ◽  
Homo Lumo

Double metal amidoborans are considered to the most promising candidates for metal amidoborans. In this paper, the crystal structures, electronic properties, chemical bonds, hydrogen removal energies, and HOMO-LUMO of NaAB, NaLiAB, and NaMgAB have been studied. The GGA corrected density functional theory have been employed in the first principles calculations. Due to the alkali and alkali earth metals coexisting, the crystal structures of these compounds change significantly and the B–H, N–H and B-N bond lengths shorten. Moreover, the band structures and density of states of NaAB, NaLiAB, and NaMgAB were calculated. The charge density distributions and bond populations are used to understand the nature of bonding. The hydrogen removal energy states removing H(B) and H(N) from NaLiAB more easily than NaAB and NaMgAB. In addition, the frontier molecular orbital reveals that the intermolecular and intramolecular dehydrogenation of NaLiAB and NaMgAB may concur. The calculated HOMO-LUMO energy gaps suggest that the chemical reactivity is: NaLiAB> NaAB> NaMgAB.

Thermodynamic Stability of Hexagonal and Rhombohedral Bn at Cvd Conditions from Van der Waals Corrected First Principles Calculations

2019 ◽  
Author(s):  
Henrik Pedersen ◽  
Björn Alling ◽  
Hans Högberg ◽  
Annop Ektarawong
Keyword(s):  
Thin Films ◽  
Thermodynamic Stability ◽  
First Principles ◽  
Thermal Equilibrium ◽  
Density Functional ◽  
Van Der Waals ◽  
Chemical Vapor ◽  
First Principles Calculations ◽  
Functional Theory ◽  
The Stability

Thin films of boron nitride (BN), particularly the sp<sup>2</sup>-hybridized polytypes hexagonal BN (h-BN) and rhombohedral BN (r-BN) are interesting for several electronic applications given band gaps in the UV. They are typically deposited close to thermal equilibrium by chemical vapor deposition (CVD) at temperatures and pressures in the regions 1400-1800 K and 1000-10000 Pa, respectively. In this letter, we use van der Waals corrected density functional theory and thermodynamic stability calculations to determine the stability of r-BN and compare it to that of h-BN as well as to cubic BN and wurtzitic BN. We find that r-BN is the stable sp<sup>2</sup>-hybridized phase at CVD conditions, while h-BN is metastable. Thus, our calculations suggest that thin films of h-BN must be deposited far from thermal equilibrium.

scholarly journals Anion ordering and vacancy defects in niobium perovskite oxynitrides

2021 ◽  
Vol 2 (7) ◽  
pp. 2398-2407
Author(s):  
Joshua J. Brown ◽  
Youxiang Shao ◽  
Zhuofeng Ke ◽  
Alister J. Page
Keyword(s):  
First Principles ◽  
First Principles Calculations ◽  
Defect Engineering ◽  
Vacancy Defects ◽  
The Stability

First-principles calculations predict the stability and mobility of vacancy defects in niobium perovskite oxynitrides, aiding defect engineering for enhanced photocatalysis.

SOLVENT EFFECTS ON THE ELECTRONIC STRUCTURE AND NON-LINEAR OPTICAL PROPERTIES OF PYRENE AND SOME OF ITS DERIVATIVES BASED ON DENSITY FUNCTIONAL THEORY

2021 ◽  
Vol 4 (4) ◽  
pp. 236-251
Author(s):  
A. S. Gidado ◽  
L. S. Taura ◽  
A. Musa
Keyword(s):  
Density Functional Theory ◽  
Gas Phase ◽  
Density Functional ◽  
Energy Gap ◽  
Chemical Reactivity ◽  
Basis Set ◽  
Lumo Energy ◽  
Functional Theory ◽  
Organic Optoelectronic ◽  
Homo Lumo

Pyrene (C16H10) is an organic semiconductor which has wide applications in the field of organic electronics suitable for the development of organic light emitting diodes (OLED) and organic photovoltaic cells (OPV). In this work, Density Functional Theory (DFT) using Becke’s three and Lee Yang Parr (B3LYP) functional with basis set 6-311++G(d, p) implemented in Gaussian 03 package was  used to compute total energy, bond parameters, HOMO-LUMO energy gap, electron affinity, ionization potential, chemical reactivity descriptors, dipole moment, isotropic polarizability (α), anisotropy of polarizability ( Δ∝) total first order hyper-polarizability () and second order hyperpolarizability (). The molecules used are pyrene, 1-chloropyrene and 4-chloropyrene  in gas phase and in five different solvents: benzene, chloroform, acetone, DMSO and water. The results obtained show that solvents and chlorination actually influenced the properties of the molecules. The isolated pyrene in acetone has the largest value of HOMO-LUMO energy gap of and is a bit closer to a previously reported experimental value of  and hence is the most stable. Thus, the pyrene molecule has more kinetic stability and can be described as low reactive molecule. The calculated dipole moments are in the order of 4-chloropyrene (1.7645 D) < 1-chloropyrene (1.9663 D) in gas phase. The anisotropy of polarizability ( for pyrene and its derivatives were found to increase with increasing polarity of the solvents.  In a nutshell, the molecules will be promising for organic optoelectronic devices based on their computed properties as reported by this work.

The stability, electronic structure, elastic and metallic properties of manganese nitrides

RSC Advances ◽  
2015 ◽  
Vol 5 (2) ◽  
pp. 1620-1627 ◽  
Author(s):  
Ran Yu ◽  
Xiaoyu Chong ◽  
Yehua Jiang ◽  
Rong Zhou ◽  
Wen Yuan ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Phase Stability ◽  
First Principles ◽  
First Principles Calculations ◽  
The Stability

The phase stability, electronic structure, and elastic and metallic properties of manganese nitrides (Mn4N, Mn2N0.86, Mn3N2, and MnN) were extensively studied by first principles calculations.

First-principles study on the stability and magnetoelectric properties of multiferroic materials XTiO3 (X = Mn, Fe, Co, Ni)

2018 ◽  
Vol 32 (09) ◽  
pp. 1850105 ◽  
Author(s):  
Xing-Yuan Chen ◽  
Guo-Xia Lai ◽  
Di Gu ◽  
Wei-Ling Zhu ◽  
Tian-Shu Lai ◽  
...  
Keyword(s):  
Magnetic Property ◽  
First Principles ◽  
Phonon Dispersion ◽  
Critical Conditions ◽  
First Principles Calculations ◽  
Multiferroic Materials ◽  
Equilibrium Conditions ◽  
Magnetoelectric Properties ◽  
Strong Hybridization ◽  
The Stability

The XTiO3 (X = Mn, Fe, Co and Ni) materials with R3c structure could be grown under critical conditions based on first-principles calculations and thermodynamic stability analysis. FeTiO3 and MnTiO3 could be synthesized relatively easily under metal-rich and O-poor conditions, while NiTiO3 could be stable under Ni-rich, O-rich and Ti-poor conditions. The predicted R3c CoTiO3 under thermodynamic equilibrium conditions is suggested to be synthesized under Co-rich, O-rich and Ti-poor conditions, but the calculated phonon dispersion indicates R3c CoTiO3 becomes unstable under the dynamical conditions. The ferroelectric behavior in the XTiO3 (X = Mn, Fe, Co and Ni) system could be dominated by the Ti ion with d0 state and the strong hybridization between Ti and O, while the magnetic property is mainly caused by the contribution of 3d transition metal.

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