Atomic Orbitals
Mostrando 1-12 de 28 artigos, teses e dissertações.
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1. ORBITALS IN GENERAL CHEMISTRY, PART II: MATHEMATICAL REALITIES
In Part II of a three-part series, we discuss two factors absent from textbooks of general chemistry that are important in a discussion of teaching orbitals. First, atomic orbitals are shown systematically to comprise algebraic formulae in coordinates of not one but four sets (spherical polar, paraboloidal, ellipsoidal, spheroconical coordinates). Each formu
Quím. Nova. Publicado em: 2021-03
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2. HPV infection - Screening, diagnosis and management of HPV-induced lesions
In Part II of a three-part series, we discuss two factors absent from textbooks of general chemistry that are important in a discussion of teaching orbitals. First, atomic orbitals are shown systematically to comprise algebraic formulae in coordinates of not one but four sets (spherical polar, paraboloidal, ellipsoidal, spheroconical coordinates). Each formu
Rev. Bras. Ginecol. Obstet.. Publicado em: 2021-03
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3. HYBRID ATOMIC ORBITALS IN ORGANIC CHEMISTRY. PART 1: CRITIQUE OF FORMAL ASPECTS
The importance of hybrid atomic orbitals, both historically and mathematically, is reviewed. Our new analysis of the original derivation of the sp3, sp2, sp model reveals serious errors. Based on a critical survey of the literature, we submit six formal criteria that deprecate the use of hybrid orbitals in a pedagogical context. A sound mathematical basis of
Quím. Nova. Publicado em: 26/08/2019
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4. HYBRID ATOMIC ORBITALS IN ORGANIC CHEMISTRY. PART 2: CRITIQUE OF PRACTICAL ASPECTS
The importance of hybrid atomic orbitals, in both general and organic chemistry, is reviewed. Every contemporary textbook of organic chemistry introduces the directed-valence (e.g. sp3, sp2, sp) model, but the suitability of these hybrid orbitals for use in the teaching of molecular structure has been increasingly questioned. Based on a critical survey of th
Quím. Nova. Publicado em: 26/08/2019
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5. A smooth path to plot hydrogen atom via Monte Carlo method
Abstract In this paper, we show how to build a basic computer program using the Monte Carlo method to display the hydrogen atomic orbitals. For this, in a heuristic way, we applied a von Neumann acceptance-rejection method in simple problems of potential wells, and we end with the hydrogen orbitals representation. In this technique, we spread points uniforml
Rev. Bras. Ensino Fís.. Publicado em: 22/07/2019
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6. ANÁLISE DA ABORDAGEM HISTÓRICA PARA A TABELA PERIÓDICA EM LIVROS DE QUÍMICA GERAL PARA O ENSINO SUPERIOR USADOS NO BRASIL NO SÉCULO XX
The aim of this paper was to analyze the historical approaches to the periodic table in general chemistry textbooks used in Brazilian universities in the twentieth century. Textbooks were qualitatively analyzed according to the following criteria: position of the discussion about the periodic table in the book; presence or absence of a specific chapter on th
Quím. Nova. Publicado em: 2015-05
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7. Collision-Induced Dissociation Analysis of Brevianamide A and C in Electrospray Ionization Mass Spectrometry
Brevianamides A and C are isomeric cyclic peptides with several reported biological activities, isolated from diverse microorganisms. Currently, there has been no previous investigation of brevianamide fragmentation utilizing electrospray ionization mass spectrometry (ESI-MS). In this work experiments were carried out in the positive mode using two different
J. Braz. Chem. Soc.. Publicado em: 2015-04
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8. Modulating the electronic structure of amino acids: interaction of model lewis acids with anthranilic acid
On the basis of theoretical B3LYP calculations, Yáñez and co-workers (J. Chem. Theory Comput. 2012, 8, 2293) illustrated that beryllium ions are capable of significantly modulating (changing) the electronic structures of imidazole. In this computational organic chemistry study, the interaction of this β-amino acid and five model Lewis acids (BeF1+, Be2+,
Quím. Nova. Publicado em: 2014
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9. Química e filosofia: rumo a uma frutífera colaboração
This review seeks to present a brief history of the philosophy of chemistry and the major issues discussed in the framework of this emerging discipline of philosophy of science, such as the question of physicalist reductionism and physical and chemical causality. In this vein, it also addresses the current debate over relevant issues of chemical world such a
Quím. Nova. Publicado em: 2013
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10. Caracterização estrutural e eletrônica da zircônia pura e com defeitos e impurezas / Structural and electronic characterization of zirconia, pristine and with impurities
In this investigation we studied the electronic properties and the structural stabilities of zirconia (ZrO2), as well as oxygen vacancy and Ce substitutional impurity. The investigations were carried by computational simulations using ab initio methods, based on the density functional theory and the APW + lo (Aumengted Plane Waves plus local orbitals) method
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 09/12/2011
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11. Conjuntos de bases gaussianas para os átomos de H até Ar : aplicações em cálculos HF, MP2 E DFT de propriedades elétricas e magnéticas moleculares
Conjunto de bases Gaussianas aumentado de qualidade quíntupla zeta de valência mais funções de polarização (A5ZP) para o H e Li até Ar foi apresentado. Esse conjunto foi determinado a partir do conjunto de bases 5ZP por adição de funções difusas (simetrias s e p) e de polarização (simetrias p, d, f, g e h), que foram otimizadas para o ânion aos
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 26/03/2010
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12. First-principles study of carbon chemisorption on γ-Fe(111) surface
In order to study the interaction between γ-Fe and carbon, the geometry structures, surface relaxations, adsorption energies and electronic structures for carbon chemisorption at four different adsorption sites on γ-Fe(111) surface at a monolayer coverage of 1 were studied using density functional theory. The electronic structures were compared with the ch
Brazilian Journal of Physics. Publicado em: 2010-12