New insight into the intrinsic instability of fcc ZrH2 by energy-resolved local bonding analysis

RSC Advances ◽  
2016 ◽  
Vol 6 (23) ◽  
pp. 19150-19154 ◽  
Author(s):  
Xin Wang ◽  
Rui-Zhi Qiu ◽  
Ya-Jiang Xian ◽  
Yu-Ting Zhang ◽  
Peng-Chuang Liu ◽  
...  
Keyword(s):  
Bonding Analysis ◽  
Local Bonding ◽  
Insight Into

The intrinsic instability of fcc ZrH2 stems from the peak of T2g and Eg orbitals at EF.

scholarly journals Synthesis, Structure and Bonding Analysis of the Zwitterionic PPP-Pincer Complex (6-Ph2P-Ace-5-)2P(O)AuCl2

Crystals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 564
Author(s):  
Daniel Duvinage ◽  
Enno Lork ◽  
Simon Grabowsky ◽  
Stefan Mebs ◽  
Jens Beckmann
Keyword(s):  
Molecular Structure ◽  
Electron Pair ◽  
Real Space ◽  
X Ray ◽  
Bonding Analysis ◽  
X Ray Crystallography ◽  
Pincer Complex ◽  
Structure And Bonding ◽  
Covalent Interactions ◽  
Insight Into

The reaction of (6-Ph2P-Ace-5-)2P(O)H with (tht)AuCl3 proceeds via elimination of tetrahydrothiophene (tht) and HCl, providing the zwitterionic PPP-pincer complex (6-Ph2P-Ace-5-)2P(O)AuCl2 (1) as yellow crystals. The molecular structure of 1 was established and studied by X-ray crystallography. The electronic structure was computationally analyzed using a comprehensive set of real-space bonding indicators derived from electron and electron-pair densities, providing insight into the relative contributions of covalent and non-covalent forces to the polar-covalent Au–Cl, Au–P, and P–O− bonds; the latter being one of the textbook cases for strongly polarized covalent interactions. Partial spatial complementarity between both bonding aspects is suggested by the electronic properties of the distinctively different Au–Cl bonds.

Local bonding analysis of the valence and conduction band features of TiO2

2007 ◽  
Vol 102 (3) ◽  
pp. 033707 ◽  
Author(s):  
L. Fleming ◽  
C. C. Fulton ◽  
G. Lucovsky ◽  
J. E. Rowe ◽  
M. D. Ulrich ◽  
...  
Keyword(s):  
Conduction Band ◽  
Bonding Analysis ◽  
Local Bonding

scholarly journals 1st Row Transition Metal Aluminylene Complexes: Preparation, Properties and Bonding Analysis

2021 ◽  
Author(s):  
Richard Y Kong ◽  
Mark Crimmin
Keyword(s):  
Transition Metal ◽  
Ab Initio ◽  
Long Range ◽  
Short Range ◽  
Dispersion Interactions ◽  
Metal Centre ◽  
Bonding Analysis ◽  
Metal Metal ◽  
Spectroscopic Characterisation ◽  
Insight Into

<i>The synthesis and spectroscopic characterisation of eight new first-row transition metal (M = Cr, Mn, Fe, Co, Cu) aluminylene complexes is reported. DFT and ab<b> </b>initio calculations have been used to provide detailed insight into the metal–metal bond. The σ-donation and π-backdonation properties of the aluminylene ligand are evaluated via NBO and ETS-NOCV calculations. These calculations reveal that these ligands are strong σ-donors but also competent π-acceptors. These properties are not fixed but vary in response to the nature of the transition metal centre, suggesting that aluminylene fragments can modulate their bonding to accommodate both electron-rich and electron-poor transition metals. Ab initio<b> </b>DLPNO-CCSD(T) calculations show that dispersion plays an important role in stabilising these complexes. Both short-range and long-range dispersion interactions are identified. These results will likely inform the design of next-generation catalysts based on aluminium metalloligands. </i>

scholarly journals 1st Row Transition Metal Aluminylene Complexes: Preparation, Properties and Bonding Analysis

2021 ◽  
Author(s):  
Richard Y Kong ◽  
Mark Crimmin
Keyword(s):  
Transition Metal ◽  
Ab Initio ◽  
Long Range ◽  
Short Range ◽  
Dispersion Interactions ◽  
Metal Centre ◽  
Bonding Analysis ◽  
Metal Metal ◽  
Spectroscopic Characterisation ◽  
Insight Into

<i>The synthesis and spectroscopic characterisation of eight new first-row transition metal (M = Cr, Mn, Fe, Co, Cu) aluminylene complexes is reported. DFT and ab<b> </b>initio calculations have been used to provide detailed insight into the metal–metal bond. The σ-donation and π-backdonation properties of the aluminylene ligand are evaluated via NBO and ETS-NOCV calculations. These calculations reveal that these ligands are strong σ-donors but also competent π-acceptors. These properties are not fixed but vary in response to the nature of the transition metal centre, suggesting that aluminylene fragments can modulate their bonding to accommodate both electron-rich and electron-poor transition metals. Ab initio<b> </b>DLPNO-CCSD(T) calculations show that dispersion plays an important role in stabilising these complexes. Both short-range and long-range dispersion interactions are identified. These results will likely inform the design of next-generation catalysts based on aluminium metalloligands. </i>

scholarly journals Bonding Analysis of Compounds with Unusual Coordination of Carbon: Proposed Symmetric Systems with Six-Coordinate Carbon

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3937
Author(s):  
Carl Trindle ◽  
Zikri Altun ◽  
Erdi Ata Bleda
Keyword(s):  
Computational Modeling ◽  
Electron Density ◽  
Coordination Sphere ◽  
Experimental Validation ◽  
Electron Localization ◽  
Aim Analysis ◽  
Bonding Analysis ◽  
Localization Function ◽  
Insight Into ◽  
Symmetric Systems

The possibility of carbon tetravalence in geometries other than tetrahedral and of carbon hypervalence has been taken seriously since the 1970s. Computational modeling and subsequent experimental validation have established the existence of molecules with carbon atoms with planar tetravalence and as many as six objects in carbon’s coordination sphere. In this work, we develop insight into the nature of bonding to carbon in these unusual environs as provided by Bader’s Atoms in Molecules (AIM) analysis of the electron density, along with the electron localization function (ELF) and the non-covalent index (NCI). We review several well-established systems (spiropentadiene dication, hexamethyl benzene dication, dimethanospiro[2.2]octaplane dication, and 1,8-dimethoxy-9-dimethoxyanthracene cation) and propose new D2d–symmetric variants of a hexacoordinated species.

Calibration problems in hydrogen luminosities

1966 ◽  
Vol 24 ◽  
pp. 322-330
Author(s):  
A. Beer
Keyword(s):  
Galactic Structure ◽  
B Stars ◽  
Insight Into

The investigations which I should like to summarize in this paper concern recent photo-electric luminosity determinations of O and B stars. Their final aim has been the derivation of new stellar distances, and some insight into certain patterns of galactic structure.

Stochasting modeling of planetary ring systems

1984 ◽  
Vol 75 ◽  
pp. 461-469 ◽  
Author(s):  
Robert W. Hart
Keyword(s):  
Maximum Entropy ◽  
Ring System ◽  
The Sun ◽  
Ultimate State ◽  
Interparticle Interactions ◽  
Ring Systems ◽  
First Order ◽  
Planetary Ring ◽  
Insight Into

ABSTRACTThis paper models maximum entropy configurations of idealized gravitational ring systems. Such configurations are of interest because systems generally evolve toward an ultimate state of maximum randomness. For simplicity, attention is confined to ultimate states for which interparticle interactions are no longer of first order importance. The planets, in their orbits about the sun, are one example of such a ring system. The extent to which the present approximation yields insight into ring systems such as Saturn's is explored briefly.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

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