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Quantum chemical calculation of nickel and copper atomic valencies in crystalline oxides

A new quantum chemical definition is proposed of the full atomic valence, VA, taking into account both the covalent and ionic parts of the chemical bonds formed by atoms in molecules and crystals. The full atomic valencies, covalencies, and charges on atoms are calculated for nickel–oxygen crystalline compounds in the CNDO band theory approximation. A comparison of the chemical bonding in nickel a

The electronic structure of crystalline nickel oxides

The electronic structure of eleven crystalline nickel oxides was investigated by band theory - CNDO method. Both the band and local properties of the electronic structure were calculated and were used for the description of chemical bonding in Ni(II) (NiO, Li2NiO2, Na2NiO2, K2NiO2, BaNiO2, La2NiO4), Ni(III) (LiNiO2, NaNiO2, LaNiO3) and Ni(IV) (BaNiO3) compounds.

Influence of ammonium on formation of mineral-associated organic carbon by an ectomycorrhizal fungus

The interactions between dissolved organic matter (DOM) and mineral particles are critical for the stabilization of soil organic matter (SOM) in terrestrial ecosystems. The processing of DOM by ectomycorrhizal fungi contributes to the formation of mineral-stabilized SOM by two contrasting pathways: the extracellular transformation of DOM (ex vivo pathway) and the secretion of mineral-surface-react

The Electronic Structure and the Chemical Bonding in NiO and La2NiO4 Crystals : A Comparison with CuO and La2CuO4

Modelling from quantum chemical data of the chemical bonding in NiO and La2NiO4 crystals comparatively to CuO and La2CuO4, is proposed. The increase of the ionicity degree of the Ni(II)–O bonding in comparison with Cu(II)‐O bonding is observed. The covalency is low and equally distributed in the equatorial plane and apical direction in the NiO6 octahedra in La2NiO4. As a supplementary data, which

Quantum-chemical definition of the atomic valence in molecules and crystals

A new quantum-chemical definition is given of the full atomic valence taking into account both the covalent and ionic parts of the chemical bonds formed by an atom in molecules and crystals. Full valence is close to formal ("classical") valence of an atom in a wide row of compounds. The theoretical consideration and the CNDO calculations of molecules and crystals are made to justify the validity o

The Electronic Structure of Copper Oxide Crystalline Compounds : II. Chemical Bonding in Copper–Oxygen Crystals

The crystalline structure of copper‐oxygen compounds with copper atom in the oxidation states I, II, and III is reviewed. A calculation is made of the electronic structure of the row of crystals with copper‐oxygen bonding. It is shown that the covalence effects are essential for copper oxide compounds containing copper atoms in oxydation states CuII and CuIII LUC‐CNDO calculations of La2CuO4 and Y

Early repair of trauma-related full-thickness rotator cuff tears does not eliminate the problem of healing failure

AIMS: Failure of healing is a well-known problem after repair of the rotator cuff. This study aimed to investigate if early repair of trauma-related full-thickness rotator cuff tears (FTRCTs) could prevent this failure. PATIENTS AND METHODS: In this prospective trial, 62 consecutive patients (14 women (23%), 48 men (77%); median age 61 years (interquartile range (IQR) 54 to 65)) with trauma-relate

Application of embedded-cluster models in the theory of local centres in graphite

Different approaches to the theoretical study of the local centres in solids are discussed. Particular attention is paid to the embedded-cluster models. There are given the mathematical formulation, the computational scheme and applications for some local centres on/in graphite monolayers of the moderately large embedded cluster and the large-unit-cell-embedded-cluster (LUC-EC) models. It is shown

ABO blood type and risk of porcine bioprosthetic aortic valve degeneration : SWEDEHEART observational cohort study

Objective Blood type A antigen on porcine aortic bioprostheses might initiate an immune reaction leading to an increased frequency of structural valve deterioration in patients with blood type B or O. The aim was to analyse the association between ABO blood type and porcine bioprosthetic aortic valve degeneration. Design Observational nationwide cohort study. Setting Swedish population-based study

Preserving Preclinical PET Quality During Intratherapeutic Imaging in Radionuclide Therapy with Rose Metal Shielding Reducing Photon Flux

Performing PET imaging during ongoing radionuclide therapy can be a promising method to follow tumor response in vivo. However, the high therapeutic activity can interfere with the PET camera performance and degrade both image quality and quantitative capabilities. As a solution, low-energy photon emissions from the therapeutic radionuclide can be highly attenuated, still allowing sufficient detec