11B NMR Chemical Shift Predictions via Density Functional Theory and Gauge-Including Atomic Orbital Approach: Applications to Structural Elucidations of Boron-Containing Molecules

A versatile synthetic building block, 2-amino-1,10-phenanthrolin-1-ium chloride (L∙HCl) was synthesized and characterized by IR, 1H and 13C NMR DEPT analysis, UV/Vis and single-crystal X-ray diffraction technique. The molecular geometry, vibrational wavenumbers and gauge including atomic orbital (GIAO), 1H and 13C NMR chemical shifts values of the title compound in the ground state were obtained by using density functional theory (DFT/B3LYP) method with 6-311++G(d,p) basis set and compared with the experimental data. Electronic absorption spectrum of the salt was determined using the time-dependent density functional theory (TD-DFT) method at the same level. In the NMR and electronic absorption spectra calculations, the effect of solvent on the theoretical parameters was included using the default model with DMSO as solvent. The obtained theoretical parameters agree well with the experimental findings.

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Structural Stability and Thermodynamic Properties of (Y2O3)n(n=1-15) Clusters Based on Density Functional Theory

10.22541/au.162196237.76163897/v1 ◽

2021 ◽

Author(s):

Xin Jiang ◽

Zhenming Zhang ◽

Diqiang Luo ◽

Jinglin You ◽

Chaobin Lai

Keyword(s):

Density Functional Theory ◽

Thermodynamic Properties ◽

Yttrium Oxide ◽

Density Functional ◽

Atomic Orbital ◽

Cluster Structure ◽

Functional Theory ◽

Average Binding Energy ◽

Bee Colony ◽

Different Temperatures

The initial configuration of Yttrium oxide clusters (Y2O3)n(n=1-15) was creatively constructed by combining artificial bee colony algorithm with density functional theory. The structures of large and medium-sized yttrium oxide clusters with molecular number greater than 10 were established for the first time, and many new structures that are different from existing research have been obtained. The average binding energy, second-order difference energy, HOMO-LUMO gap, density of states and other properties of the clusters were analyzed. The thermodynamic properties and behavior of nano yttrium oxide clusters at different temperatures and sizes were discussed. Studies have shown that for small-sized clusters, the atomic stacking structure is cage-like, while for medium-sized and large-sized clusters, the composite trapezoidal structure and ellipsoid-like structure are more stable. The nanoclusters tend to be stable as a whole, and the relative stability of the cluster structure is higher when n = 2,4,7,9. The effect of yttrium oxygen atomic orbital on bonding is analyzed. The heat capacity (Cp), enthalpy change (H) and entropy (S) of (Y2O3)n (n=1-15) clusters increase with the increase of temperature (T), and the vibration free energy (Gv) decreases with the increase of T. The stability of the clusters changes in the temperature range of 300K-500K.

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Density Functional Theory Based Modeling of the Corrosion on Iron Surfaces

Archives of Metallurgy and Materials ◽

10.2478/v10172-012-0190-5 ◽

2013 ◽

Vol 58 (2) ◽

pp. 321-323 ◽

Cited By ~ 3

Author(s):

N. Nunomura ◽

S. Sunada

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Atomic Orbital ◽

Atomic Layer ◽

Iron Surface ◽

Basis Set ◽

Water Molecules ◽

Aqueous Corrosion ◽

Functional Theory ◽

Adsorption Of Water

In order to understand the first steps of the aqueous corrosion of iron, we have performed density functional theory (DFT) based calculations for water molecules and pre-covered oxygen on iron surface. The surface structure is modeled by iron atomic layer and vacuum region, and then oxygen atom and water molecules are displaced on the surface. Self consistent DFT calculations were performed using a numerical atomic orbital basis set and a norm-conserve pseudopotential method. According to our calculations, with increasing surface oxygen coverage, the iron surface is found to be not activated, which leads to a feeble adsorption of water molecules on iron surface. Our results show that the surface covered oxygen exerts an influence on the adsorption of water molecules on iron surface.

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Molecular structure, vibrational and chemical shift assignments of 8-hydroxy-1-methylquinolinium iodide hydrate by density functional theory (DFT) and ab initio Hartree-Fock (HF) calculations

Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy ◽

10.1016/j.saa.2008.01.037 ◽

2008 ◽

Vol 71 (3) ◽

pp. 760-765 ◽

Cited By ~ 7

Author(s):

Yusuf Atalay ◽

Davut Avcı ◽

Adil Başoğlu

Keyword(s):

Molecular Structure ◽

Density Functional Theory ◽

Chemical Shift ◽

Ab Initio ◽

Density Functional ◽

Chemical Shift Assignments ◽

Functional Theory ◽

Hartree Fock ◽

Hf Calculations

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Graphite as A Hydrogen Storage in Fuel Cell System: Computational Material Study for Renewable Energy

Jurnal ILMU DASAR ◽

10.19184/jid.v17i2.3499 ◽

2017 ◽

Vol 17 (2) ◽

pp. 103

Author(s):

Rahmat Gunawan ◽

Cynthia Linaya Radiman ◽

Muhamad Abdulkadir Martoprawiro ◽

Hermawan K. Dipojono

Keyword(s):

Density Functional Theory ◽

Hydrogen Storage ◽

Density Functional ◽

Alkali Metals ◽

Correlation Energy ◽

Atomic Orbital ◽

Hydrogen Gas ◽

Basis Set ◽

Functional Theory ◽

Orbital Contribution

The Hydrogen storage based-graphite materials have been investigated theoretically via Density Functional Theory (DFT) approach. The native graphite was compared to the modified graphite, namely the intercalation graphite (GICs, graphite intercalated compounds). Here the GICs was intercalated by alkali metals (Li, Na and K). The electronic structures, energetics and atomic orbital contributions of hydrogen-graphite system, GICs, and hydrogen-GICs were studied by calculation approach of gradient corrected PBE (Perdew-Burke-Ernzerhof) for recovery of exchange-correlation energy. The calculation was supported by using basis set of the plane waves whereas the computation of electron-core by using Ultrasoft Vanderbilt pseudopotential. The computational calculation provides four main studies i.e. molecular geometry relaxation, determination of electronic bands structure of energy, energy state density (DOS) and atomic orbital contribution by charge density differences.Keywords: Density Functional Theory, hydrogen gas, graphite intercalated material

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