FT-IR, FT-Raman, dispersive Raman, NMR spectroscopic studies and NBO analysis of 2-Bromo-1H-Benzimidazol by density functional method
TL;DR: In this article, 2-Bromo-1H-Benzimidazol (abbreviated as 2Br1HB) was analyzed using DFT/B3LYP with 6-311+G(d,p) basis set.
About: This article is published in Journal of Molecular Structure.The article was published on 2015-02-05. It has received 17 citations till now. The article focuses on the topics: Mulliken population analysis & HOMO/LUMO.
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TL;DR: In this paper, the structure-property relationship and effects of end-capped units on D1-D4 are theoretically calculated and compared with reference molecule R. This theoretical designed model confirms that the endcapped unit modifications proves an efficient alternative solution in achieving the desired optoelectronic properties.
61 citations
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TL;DR: In this article, the vibrational analysis of pyrogallol was investigated in solid phase by FT-IR and FT-Raman spectroscopic techniques in the region 4000-400 cm−1 and 4000-40 cm −1, respectively.
39 citations
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TL;DR: In this paper, the structural properties, vibrational assignments, chemical shifts, electronic properties and other molecular parameters of 4-hydroxy carbazole have been determined and comprehensively discussed.
14 citations
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TL;DR: In this article, an essential biochemical indicator L-pipecolinic acid for diagnosis of chronic diseases like peroxisomal disorder has been identified for the first time from Calotropis gigantea flowers using GC-MS method.
13 citations
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TL;DR: In this article, the effect of pyrogallol on the flotation performance of bismuthinite was evaluated using flotation tests, and associated interaction mechanisms were investigated by using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectrography (XPS), and density functional theory (DFT) calculations.
12 citations
References
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TL;DR: In this article, a semi-empirical exchange correlation functional with local spin density, gradient, and exact exchange terms was proposed. But this functional performed significantly better than previous functionals with gradient corrections only, and fits experimental atomization energies with an impressively small average absolute deviation of 2.4 kcal/mol.
Abstract: Despite the remarkable thermochemical accuracy of Kohn–Sham density‐functional theories with gradient corrections for exchange‐correlation [see, for example, A. D. Becke, J. Chem. Phys. 96, 2155 (1992)], we believe that further improvements are unlikely unless exact‐exchange information is considered. Arguments to support this view are presented, and a semiempirical exchange‐correlation functional containing local‐spin‐density, gradient, and exact‐exchange terms is tested on 56 atomization energies, 42 ionization potentials, 8 proton affinities, and 10 total atomic energies of first‐ and second‐row systems. This functional performs significantly better than previous functionals with gradient corrections only, and fits experimental atomization energies with an impressively small average absolute deviation of 2.4 kcal/mol.
87,732 citations
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TL;DR: Numerical calculations on a number of atoms, positive ions, and molecules, of both open- and closed-shell type, show that density-functional formulas for the correlation energy and correlation potential give correlation energies within a few percent.
Abstract: A correlation-energy formula due to Colle and Salvetti [Theor. Chim. Acta 37, 329 (1975)], in which the correlation energy density is expressed in terms of the electron density and a Laplacian of the second-order Hartree-Fock density matrix, is restated as a formula involving the density and local kinetic-energy density. On insertion of gradient expansions for the local kinetic-energy density, density-functional formulas for the correlation energy and correlation potential are then obtained. Through numerical calculations on a number of atoms, positive ions, and molecules, of both open- and closed-shell type, it is demonstrated that these formulas, like the original Colle-Salvetti formulas, give correlation energies within a few percent.
84,646 citations
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TL;DR: In this article, the ground state of an interacting electron gas in an external potential was investigated and it was proved that there exists a universal functional of the density, called F[n(mathrm{r})], independent of the potential of the electron gas.
Abstract: This paper deals with the ground state of an interacting electron gas in an external potential $v(\mathrm{r})$. It is proved that there exists a universal functional of the density, $F[n(\mathrm{r})]$, independent of $v(\mathrm{r})$, such that the expression $E\ensuremath{\equiv}\ensuremath{\int}v(\mathrm{r})n(\mathrm{r})d\mathrm{r}+F[n(\mathrm{r})]$ has as its minimum value the correct ground-state energy associated with $v(\mathrm{r})$. The functional $F[n(\mathrm{r})]$ is then discussed for two situations: (1) $n(\mathrm{r})={n}_{0}+\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{n}(\mathrm{r})$, $\frac{\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{n}}{{n}_{0}}\ensuremath{\ll}1$, and (2) $n(\mathrm{r})=\ensuremath{\phi}(\frac{\mathrm{r}}{{r}_{0}})$ with $\ensuremath{\phi}$ arbitrary and ${r}_{0}\ensuremath{\rightarrow}\ensuremath{\infty}$. In both cases $F$ can be expressed entirely in terms of the correlation energy and linear and higher order electronic polarizabilities of a uniform electron gas. This approach also sheds some light on generalized Thomas-Fermi methods and their limitations. Some new extensions of these methods are presented.
38,160 citations