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A Simplified Approach to the Density Functional Theory of Molecules Christian Kollmar Organisch-Chemisches Institut, Winterthurerstr. 190, Universität Zürich, CH-8057 Zürich Z. Naturforsch. 54 a, 101-109 (1999); received December 2, 1998 A simplified molecular orbital (MO) formalism based on density functional theory is developed. Starting from the same energy expression as Kohn-Sham theory the electronic density is expanded in terms of atomic mono-center densities. Application of the variational principle leads to a secular matrix with a particularly

A Theoretical Study of Lithium-Doped Gallium Clusters by Density Functional Theory Şükrü Şentürk and Yavuz Ekincioğlu Department of Physics, Dumlupınar University, 43100 Kutahya, Turkey Reprint requests to Ş. Ş.; E-mail: senturkskr@ymail.com Z. Naturforsch. 67a, 289 – 295 (2012) / DOI: 10.5560/ZNA.2012-0017 Received June 27, 2011 / revised November 2, 2011 The geometrical structures, stabilities, and electronic properties of GanLi (n = 1 – 13) clusters were investigated within the density functional theory (DFT). The impurity lithium atom enhances the

the pharmacological activity sites of catechins. Figure 1 Chemical structures of four catechins (A represents A-ring, B represents B-ring, C represents C-ring and D represents D-ring). In this study, we performed density functional theory (DFT) simulations to study the interaction of typical catechins and cholesterol and analyze the adsorption sites between them. Our results demonstrated that the adsorption sites of the most stable complexes of EC–Chol and EGC–Chol are all on the A-ring, while the adsorption sites of ECG–Chol and EGCG–Chol are on the B-ring and

A dispersion-corrected density-functional theory study of small molecules adsorbed in alkali-exchanged chabazites Michael Fischer* and Robert G. Bell* Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK Received July 10, 2011; accepted September 17, 2012 Published online: October 29, 2012 Zeolites / Chabazite / Density-functional theory / Gas adsorption / Carbon dioxide Abstract. Recently, the removal of carbon dioxide from gas mixtures containing methane or nitrogen has received considerable attention, as it could help to

should be less than unity. The S values larger than unity obtained in our FC experiments suggested that the observed H/D isotope effects should be analyzed and elucidated based on the theory of equilibrium isotope effects. To elucidate the H/D isotope effects we observed, we calculated equilibrium constants of hydrogen isotope exchange reactions expected to occur during FC operations by the density functional theory (DFT) in the same article [1]. The H/D isotope exchange equilibrium between the electrode catalyst phase and the electrolyte membrane phase is expressed

→ 2 H transition at a temperature of about 1280–1300 K ( Frey et al. 1986 ). There exists a third, high-pressure polymorph of ZnS, characterized by a halite-like structure (NaCl), with octahedral coordination of the ions, which is called rock salt (rs) ZnS (space group Fm ͞3 m ). Figure 1 Wurtzite unit-cell model, with zinc and sulfur atoms colored in dark gray and light gray, respectively. In a very recent work we investigated in details by ab initio density functional theory (DFT) simulations the thermodynamic and thermoelastic behavior of both cubic polymorphs

modulate the reactivity of other free radicals [1–18]. Recently, several studies were published reporting on the results of quantum chemical calculations of the detailed electronic structures of pterin (2-amino-3H-pteridine-4-on) and derivatives employing density functional theory (DFT) with reasonably sized basis sets [19–22]. In the present investigation, I report on such calculations extended to the five radicals derived from the most stable tautomeric form of neutral pterin by homolytic elimination of each one of the five hydrogen atoms present in pterin. In order to

Abstract

The triplet excited state properties and photosensitization mechanisms of indigo were investigated based on density functional theory calculations. The solvent effects on the photosensitization mechanisms of indigo have also been considered. The thermodynamic feasibility of the possible 1O2 and O2·−-photogeneration pathways by triplet excited state indigo in different solvents was explored, in order to gain some deeper insights into the photosensitization characters of the dye.

suggested the existence of BNTs. In 2010, Liu et al. [ 17 ] also fabricated BNTs successfully using a thermal evaporation method. By studying electric transport and field emission properties, it was found that BNT may be a promising field emission material. Using density functional theory (DFT), Liu et al. [ 18 ], [ 19 ] predicted a series of new BNTs by rolling up two different types of BS. In addition, various BNTs using a buckled triangular BS as the precursor were investigated [ 20 ], [ 21 ]. Recently, Tang and Beigi [ 22 ] predicted a novel and stable two

to the experimental ones than PBE. In the framework of the Materials Project [ 13 ] another DFT calculation of phase III has been made using the PBE functional with the VASP code instead of DMol 3 . Table 2 shows that the two codes led to similar results. Tab. 2: Experimental and DFT results for the lattice parameters and the elastic stiffness matrix of KLiSO 4 phfase III. C ij [GPa] Experiment Density functional theory Experiment DMol 3 VASP Brillouin scattering Ultrasound Mean C ij X-rays Present DFT calculations mp-6179 (2017) Pimenta et al. [ 14 ] Kabelka