scholarly journals Erratum: Vibrational Frequencies of Cerium-Oxide-Bound CO: A Challenge for Conventional DFT Methods [Phys. Rev. Lett. 125 , 256101 (2020)]

2022 ◽  
Vol 128 (1) ◽  
Author(s):  
Pablo G. Lustemberg ◽  
Philipp Plessow ◽  
Yuemin Wang ◽  
Chengwu Yang ◽  
Alexei Nefedov ◽  
...  
Keyword(s):  
Cerium Oxide ◽  
Vibrational Frequencies ◽  
Dft Methods

scholarly journals Vibrational Frequencies of Cerium-Oxide-Bound CO: A Challenge for Conventional DFT Methods

2020 ◽  
Vol 125 (25) ◽  
Author(s):  
Pablo G. Lustemberg ◽  
Philipp N. Plessow ◽  
Yuemin Wang ◽  
Chengwu Yang ◽  
Alexei Nefedov ◽  
...  
Keyword(s):  
Cerium Oxide ◽  
Vibrational Frequencies ◽  
Dft Methods

scholarly journals Quantum Mechanical Modeling of the Vibrational Spectra of Minerals with a Focus on Clays

Minerals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 141 ◽  
Author(s):  
James Kubicki ◽  
Heath Watts
Keyword(s):  
Vibrational Spectra ◽  
Density Functional ◽  
Inelastic Neutron Scattering ◽  
Isotopic Fractionation ◽  
Inelastic Neutron ◽  
Vibrational Frequencies ◽  
Quantum Mechanical ◽  
Dft Methods ◽  
Additional Information ◽  
Starting Point

We present an overview of how to use quantum mechanical calculations to predict vibrational frequencies of molecules and materials such as clays and silicates. Other methods of estimating vibrational frequencies are mentioned, such as classical molecular dynamics simulations; references are given for additional information on these approaches. Herein, we discuss basic vibrational theory, calculating Raman and infrared intensities, steps for creating realistic models, and applications to spectroscopy, thermodynamics, and isotopic fractionation. There are a wide variety of programs and methods that can be employed to model vibrational spectra, but this work focuses on hybrid density functional theory (DFT) approaches. Many of the principles are the same when used in other programs and DFT methods, so a novice can benefit from simple examples that illustrate key points to consider when modeling vibrational spectra. Other methods and programs are listed to give the beginner a starting point for exploring and choosing which approach will be best for a given problem. The modeler should also be aware of the numerous analytical methods available for obtaining information on vibrations of atoms in molecules and materials. In addition to traditional infrared and Raman spectroscopy, sum-frequency generation (SFG) and inelastic neutron scattering (INS) are also excellent techniques for obtaining vibrational frequency information in certain circumstances.

scholarly journals Assessing the accuracy of some popular DFT methods for computing harmonic vibrational frequencies of water clusters

2015 ◽  
Vol 143 (21) ◽  
pp. 214103 ◽  
Author(s):  
J. Coleman Howard ◽  
Jordan D. Enyard ◽  
Gregory S. Tschumper
Keyword(s):  
Water Clusters ◽  
Vibrational Frequencies ◽  
Dft Methods

scholarly journals Vibrational Spectroscopy Investigation Using Ab Initio and Density Functional Theory Analysis on the Structure oftert-Butyl 3a-Chloroperhydro-2,6a-epoxyoxireno[e]isoindole-5-carboxylate

2013 ◽  
Vol 2013 ◽  
pp. 1-13
Author(s):  
Hakan Arslan ◽  
Aydin Demircan ◽  
Gun Binzet ◽  
Ilhan Ozer Ilhan
Keyword(s):  
Title Compound ◽  
Density Functional ◽  
Standard Condition ◽  
Vibrational Frequencies ◽  
Basis Sets ◽  
Dft Methods ◽  
Functional Theory ◽  
Harmonic Vibrations ◽  
Infrared Intensities ◽  
Experimental Geometry

The molecular structure, vibrational frequencies, and infrared intensities of thetert-butyl 3a-chloroperhydro-2,6a-epoxyoxireno[e]isoindole-5-carboxylate were calculated by the HF and DFT (BLYP and B3LYP) methods using 6-31G(d) and 6-31G(d,p) basis sets. The FT infrared spectrum of the solid sample was measured under standard condition. We obtained two stable conformers for the title compound; however Conformer 1 is approximately 0.2 kcal/mol more stable than the Conformer 2. The comparison of the theoretical and experimental geometry of the title compound shows that the X-ray parameters fairly well reproduce the geometry of Conformer 2. Comparison of the observed fundamental vibrational frequencies of the title molecule and calculated results by HF and DFT methods indicates that B3LYP is superior for molecular vibrational problems. The harmonic vibrations computed by the B3LYP/6-31G(d,p) method are in a good agreement with the observed IR spectral data. Theoretical vibrational spectra of the title compound were interpreted by means of potential energy distributions (PEDs) using VEDA 4 program.

scholarly journals On the Relevance of Considering the Intermolecular Interactions on the Prediction of the Vibrational Spectra of Isopropylamine

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Ana M. Amado ◽  
Sónia M. Fiuza ◽  
Luis A. E. Batista de Carvalho ◽  
Paulo J. A. Ribeiro-Claro
Keyword(s):  
Hydrogen Bonding ◽  
Weak Interactions ◽  
Vibrational Frequencies ◽  
Basis Set ◽  
Vibrational Modes ◽  
Dft Methods ◽  
Torsional Mode ◽  
Computational Costs ◽  
Donor And Acceptor ◽  
The Comparative Study

The effects of implicitly considering the effects of hydrogen bonding on the molecular properties, such as vibrational frequencies, were inferred on the basis of DFT calculations. Several clusters of isopropylamine were assembled and theoretically characterized. The results showed that maximum H-bond cooperativity is achieved when the amine group acts simultaneously as donor and acceptor. The effect of H-bond cooperativity manifests itself in the relative cluster stability and on the structural and vibrational frequency predictions. Referring to the vibrational frequencies it was found that theNH2stretching and torsion vibrational modes are the most affected by the amine involvement in hydrogen bonding. Both stretching modes were found to be significantly redshifted relative to the monomer. TheNH2torsional mode, on the other hand, was found to be blueshifted up to 350 cm-1. Finally, the comparative study between the theory levels performed allows to conclude that the small 6-31G* basis set is able to stabilize weakC–H⋯Ninteractions as long as the new dispersion corrected DFT methods are considered. The impairments observed with conventional DFT methods for describing weak interactions may be overcome with the improvement of basis set, but the associated increase of computational costs may turn the calculations unfeasible.

Equilibrium geometry, vibrational frequencies, and heat of formation of HOBr, HBrO2, and HBrO3 isomers

2001 ◽  
Vol 79 (7) ◽  
pp. 1135-1144 ◽  
Author(s):  
Cristina Maria P Santos ◽  
Roberto B Faria ◽  
Juan O Machuca-Herrera ◽  
Sérgio de P Machado
Keyword(s):  
Heat Capacity ◽  
Heat Of Formation ◽  
Vibrational Frequencies ◽  
Basis Sets ◽  
Equilibrium Geometry ◽  
Dft Methods ◽  
Experimental Values ◽  
Equilibrium Geometries ◽  
Extended Basis ◽  
Ab Initio And Dft

The equilibrium geometries, vibrational frequencies, heat capacity, and heat of formation for compounds of general formula HBrOx were calculated by DFT (BP and pBP methods) with DN* and DN** numerical basis sets. The comparison of our HOBr calculated results with the HOBr experimental values points out that the BP and pBP methods are as good as other ab initio and DFT methods related in the literature employing extended basis sets. The calculated HBrOx total energy and heat of formation values, at 0 and 298.15 K, present the following order: HOBr < HBrO; HOOBr < HOBrO < HBrO2; HOOOBr < HOBrO2 < HOOBrO < HBrO3. The HBrOx heat of formation was calculated using isodesmic and homodesmic reactions and the results show that, in general, the use of these reactions gives similar results.Key words: HOBr, HBrO2, HBrO3, DFT, numerical basis.

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