Computer Simulation of Small Magnetic Clusters of 3d-Transition Metals of the Iron Subgroup Using the Hybrid Density Functional Method

This paper presents the results of s study focused on the stability of small 3d-transition-metal magnetic clusters (metals of an iron subgroup) in spin-polarized states using the hybrid density functional method. Computer modeling and full variational optimization of geometric structures of clusters were performed for various values of the spin multiplicity of electronic states. The binding energies, the bond lengths, and the frequencies of atomic zero-point vibrations in small clusters with a nuclearity of n = 2, 3, 4, 5, 6 were calculated depending on the metal (Fe, Co, Ni) and spin multiplicity M in the zero-charge state. The calculations were carried out using the hybrid density functional B3LYP method in the def2-TZVP basis set of the ORCA package algorithms. A comparison of the calculated results with the available experimental data is presented. It is shown that the calculated data obtained by the hybrid density functional method are in satisfactory agreement with the experimental data for “naked” clusters in inert media both for the spin multiplicity of the ground state and for the energy of atomic shock dissociation of clusters in inert gas flows.

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Theoretical Study of CN Radicals Chemisorption on the Electronic Properties of BC2N Nanotube

Journal of Nano Research ◽

10.4028/www.scientific.net/jnanor.48.38 ◽

2017 ◽

Vol 48 ◽

pp. 38-48 ◽

Cited By ~ 1

Author(s):

Batoul Makiabadi ◽

Mohammad Zakarianezhad ◽

Shahin Mohammadzamani

Keyword(s):

Electronic Properties ◽

Density Functional ◽

Density Functional Method ◽

Nbo Analysis ◽

Band Gap Energy ◽

Functional Method ◽

Basis Set ◽

Hybrid Density Functional ◽

Cn Radicals ◽

Covalent Nature

In this work, we have investigated the adsorption behavior of the CN radicals on electronic properties of BC2N nanotube (BC2NNT) by means of the B3LYP hybrid density functional method using 6-31G(d) basis set. The results show that CN radicals can be chemically adsorbed on the nanotube. Based on the energy analysis, the most stable position of CN radical on the nanotube is C1 site. Also, the C-side complexes are more stable than the N-side complexes. We investigated the effects of CN radicals adsorption on the electronic properties of the BC2N nanotube. According to our calculations, band gap energy of the BC2NNT decreases with increasing the number of CN radicals. It is predicted that the conductivity and reactivity of nanotube increase by increasing the number of CN radicals. Based on the NBO analysis, in all complexes charge transfer occurs from nanotube to CN radical. The AIM results show that, the Xtube…YCN interaction has covalent nature. Generally, The BC2N nanotube can be used to as sensor for nanodevice applications.

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Density Functional Theory Study of Intermolecular Interaction between RDX and H2O

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.750-752.1848 ◽

2013 ◽

Vol 750-752 ◽

pp. 1848-1851

Author(s):

Xiu Lin Zeng ◽

Xue Hai Ju

Keyword(s):

Density Functional ◽

Natural Bond Orbital ◽

Density Functional Method ◽

Zero Point ◽

Functional Method ◽

Binding Energies ◽

Basis Set ◽

Free Energies ◽

Functional Theory ◽

Dimerization Process

The density functional method of wB97xD in combination of 6-31+G** basis set was applied to the study of the heterodimers between hexahydro-1,3,5-trinitro-1,3,5-triazine and water. Three stable dimers were located. The binding energies have been corrected for the zero-point vibrational and basis set superposition errors. The largest corrected binding energy is 26.21 kJ/mol. Natural bond orbital analyses and frequency calculations were performed on each optimized structure. The thermodynamic properties of enthalpies, entropies and Gibbs free energies in the dimerization process were presented.

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Origin Invariant Full Optical Rotation Tensor in the Length Dipole Gauge without London Atomic Orbitals

10.26434/chemrxiv.14384564.v1 ◽

2021 ◽

Author(s):

Marco Caricato

Keyword(s):

Electron Correlation ◽

Density Functional ◽

Optical Rotation ◽

Density Functional Method ◽

Functional Method ◽

Basis Set ◽

Rotation Tensor ◽

Atomic Orbitals ◽

Complete Basis Set ◽

Approximate Wave

<div> <div> <div> <p>We present an origin-invariant approach to compute the full optical rotation tensor (Buckingham/Dunn tensor) in the length dipole gauge without recourse to London atomic orbitals, called LG(OI). The LG(OI) approach is simpler and less computationally demanding than the more common LG-London and modified velocity gauge (MVG) approaches and it can be used with any approximate wave function or density functional method. We report an implementation at coupled cluster with single and double excitations level (CCSD), for which we present the first simulations of the origin-invariant Buckingham/Dunn tensor in the length gauge. With this method, we attempt to decouple the effects of electron correlation and basis set incompleteness on the choice of gauge for optical rotation calculations on simple test systems. The simulations show a smooth convergence of the LG(OI) and MVG results with the basis set size towards the complete basis set limit. However, these preliminary results indicate that CCSD may not be close to a complete description of the electron correlation effects on this property even for small molecules, and that basis set incompleteness may be a less important cause of discrepancy between choices of gauge than electron correlation incompleteness. </p> </div> </div> </div>

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Role of the Solvent in Computing the 1,4-Benzosemiquinoneg-Tensor by the Coupled-Perturbed Kohn−Sham Hybrid Density Functional Method†

The Journal of Physical Chemistry B ◽

10.1021/jp031230d ◽

2004 ◽

Vol 108 (27) ◽

pp. 9449-9455 ◽

Cited By ~ 19

Author(s):

Saba M. Mattar

Keyword(s):

Density Functional ◽

Density Functional Method ◽

Functional Method ◽

Hybrid Density Functional

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A DENSITY FUNCTIONAL THEORY INVESTIGATION ON THE TAUTOMERS AND CRYSTAL OF 2-DIAZO-4,6-DINITROPHENOL

Journal of Theoretical and Computational Chemistry ◽

10.1142/s0219633604001239 ◽

2004 ◽

Vol 03 (04) ◽

pp. 599-607 ◽

Cited By ~ 4

Author(s):

XUE-HAI JU ◽

HE-MING XIAO

Keyword(s):

Density Functional ◽

Density Functional Method ◽

Lattice Energy ◽

Functional Method ◽

Basis Set ◽

Functional Theory ◽

Basis Set Superposition Error ◽

Conduction Bands ◽

Valence Bands ◽

Good Agreement

Density functional method was applied to the study of the highly efficient primary explosive 2-diazo-4,6-dinitrophenol (DDNP) in both gaseous tautomers and its bulk state. Two stable tautomers were located. It was found that the structure (I) with open diazo, i.e. with linear CNN, is more stable than that with diazo ring tautomer (II) of DDNP. The structure I is in good agreement with the structure in the bulk. The lattice energy is -89.01 kJ/mol, and this value drops to -83.29 kJ/mol when a 50% correction of the basis set superposition error was adopted. The frontier bands are quite flat. The carbon atoms in DDNP make up the upper valence bands. While the lower conduction bands mainly consist of carbon and diazo N atoms. The bond populations of C–N bonds (both C–Nitro and C–Diazo) are much less than those of the other bonds and the detonation may be initiated through the breakdown of C–N bonds.

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Density functional theory study on the molecular structure of loganin

Spectroscopy An International Journal ◽

10.1155/2011/361849 ◽

2011 ◽

Vol 25 (6) ◽

pp. 287-302 ◽

Cited By ~ 2

Author(s):

Anoop Kumar Pandey ◽

Shamoon Ahmad Siddiqui ◽

Apoorva Dwivedi ◽

Kanwal Raj ◽

Neeraj Misra

Keyword(s):

Molecular Structure ◽

Density Functional ◽

Solid Phase ◽

Density Functional Method ◽

Functional Method ◽

Basis Set ◽

Equilibrium Geometry ◽

B3lyp Method ◽

Ft Ir ◽

Detailed Interpretation

The computational Quantum Chemistry (QC) has been used for different types of problems, for example: structural biology, surface phenomena and liquid phase. In this paper we have employed the density functional method for the study of molecular structure of loganin. The equilibrium geometry, harmonic vibrational frequencies and infrared intensities were calculated by B3LYP/6-311G (d, p) method and basis set combinations. It was found that the optimized parameters obtained by the DFT/B3LYP method are very near to the experimental ones. A detailed conformational analysis was carried out. A detailed interpretation of the infrared spectra of loganin is also reported in the present work. The FT-IR spectra of loganin were recorded in solid phase. The thermodynamic calculations related to the title compound were also performed at B3LYP/6-311G (d, p) level of theory.

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