The accurate description of excited states is crucial for the development of electronic structure theory. In addition to determining excitation energies, strong state interactions arise when electronic states with the same symmetry are degenerate or...
Valence bond theory (VB) was used to determine the extent and driving forces for covalent vs. dative bonding in 10-valence-electron diatomic molecules N2, CO, NO+, CN−, P2, SiS, PS+, and SiP−. VBSCF calculations were performed at the CCSD...
A recently developed valence-bond-based multireference density functional theory, named λ-DFVB, is revisited in this paper. λ-DFVB remedies the double-counting error of electron correlation by decomposing the electron–electron int...
The determination of tungsten oxidation states and W–ligand bond lengths for pyranopterin tungsten enzymes can be negatively impacted by Fourier series termination effects and photodamage/photoreduction in the X-ray beam. As a result, a new set...
This essay describes the successive births of valence bond (VB) theory during 1916–1931. The alternative molecular orbital (MO) theory was born in the late 1920s. The presence of two seemingly different descriptions of molecules by the two theories l...
The charge distribution (CD) and the bond valence sum (BVS) methods are used to calculate the charges assignable to atomic positions in crystal structures, based on the distribution of bond lengths. Discrepancies between calculated and formal charges...
The valence bond (VB) framework is widely recognized as a powerful tool for elucidating the electronic origins of activation energy barriers in chemical reactions. We employed ab initio VB calculations to investigate the hydrogen abstraction (H-abstr...
Perovskite materials have a variety of crystal structures, and the properties of crystalline materials are greatly influenced by geometric information such as the space group, crystal system, and lattice constant. It used to be mostly obtained using...
The reaction of 2,6-diformyl-4-methylphenol (DFMF) with 1-amino-2-propanol (AP) and tris(hydroxymethyl)aminomethane (THMAM) was investigated in the presence of Cobalt(II) salts, (X = ClO4−, CH3CO2−, Cl−, NO3−), sodium azide (N...
We conducted ab initio valence bond (VB) calculations employing the valence bond self-consistent field (VBSCF) and breathing orbital valence bond (BOVB) methods to investigate the nature of the coordination bonding between ferrous heme and carbon mon...
About 70 years ago, in the framework of his theory of chemical bonding, Pauling proposed an empirical correlation between the bond valences (or effective bond orders (BOs)) and the bond lengths. Till now, this simple correlation, basic in the bond va...
This article analyzes the nature of the chemical bond in coinage metal halides using high-level ab initio Valence Bond (VB) theory. It is shown that these bonds display a large Charge-Shift Bonding character, which is traced back to the large Pauli p...
VB and molecular orbital (MO) models are normally distinguished by the fact the first looks at molecules as a collection of atoms held together by chemical bonds while the latter adopts the view that each molecule should be regarded as an independent...
Most of TM6-cluster compounds (TM = transition metal) are soluble in polar solvents, in which the cluster units commonly remain intact, preserving the same atomic arrangement as in solids. Consequently, the redox potential is often used to characteri...
The influence of Linus Pauling on the understanding of chemical bonding is critically examined. Pauling deserves credit for presenting a connection between the quantum theoretical description of chemical bonding and Gilbert Lewis’s classical bonding...
Complexes linked by various interactions are analysed in this study. They are characterized by the tetrahedral configuration of the Lewis acid centre. Interactions, being a subject of this study, are classified as σ-hole bonds, such as the halo...
The roméite-group is part of the pyrochlore-supergroup and comprises cubic oxides of A2B2X6Y formula in which Sb5+ predominates in the B-site. The A and Y main occupants determine different minerals in the group and are important for the discovery of...
The metallic state of the molecular conductor β-(meso-DMBEDT-TTF)2X (DMBEDT-TTF = 2-(5,6-dihydro-1,3-dithiolo[4,5-b][1,4]dithiin-2-ylidene)-5,6-dihydro-5,6-dimethyl-1,3-dithiolo[4,5-b][1,4]dithiin, X = PF6, AsF6) is transformed into the checkerboard-...
Our modern understanding of chemistry is predicated upon bonding interactions between atoms and ions resulting in the assembly of all of the forms of matter that we encounter in our daily life. It was not always so. This review article traces the dev...
The variety of interactions have been analyzed in numerous studies. They are often compared with the hydrogen bond that is crucial in numerous chemical and biological processes. One can mention such interactions as the halogen bond, pnicogen bond, an...
Bonding in the C2 molecule is investigated with CAS(8,8) wave functions using canonical MOs. In a subsequent step, orthogonal atomic orbitals are constructed by localizing the CASSCF MOs on the two carbon atoms with an orthogonal transformation. This...
The electrical properties of (Ba0.7Sr0.3-xCax)(Ti0.9Zr0.1)O3 (0 ≤ x ≤ 0.2) (BSCTZ) ceramics prepared using citrate gelation (CG) method were investigated by substituting Ca2+ ions for the Sr2+ sites based on the structural characteristics of th...
Density functional theory (DFT) was used to study the structure, stability, and bonding in some selected neutral pentaatomic systems, viz., CGa2Ge2, CAlGaGe2, and CSiGa2Ge containing planar tetracoordinate carbon. The systems are kinetically stable,...
The electronic structures of the first- and second-row homonuclear diatomics, XeF2, and the weakly bound dimers of nitric oxide and nitrogen dioxide molecules in their ground states are discussed in terms of molecular orbital (MO) theory and, where p...
Copper- and Mn-bearing elbaitic tourmaline (“Paraíba tourmaline”) sometimes contains significant amounts of Pb and Bi. Their position in the tourmaline crystal structure was studied with correlation analysis and bond valence calcul...
CsPbBr3 perovskite has excellent optoelectronic properties and many important application prospects in solar cells, photodetectors, high-energy radiation detectors and other fields. For this kind of perovskite structure, to theoretically predict its...
The formation of the four 3-ring systems c-(CH2)3−k(SiH2)k (k=0: cyclopropane, k=1: silirane, k=2: disilirane, k=3: cyclotrisilane) by addition of methylene and silylene to the double bond in ethene, disilene, and silaethene, as well as the eli...
The aim of this work is to predict suitable chemical compositions for the development of new ceramic oxygen gas separation membranes, avoiding doping with toxic cobalt or expensive rare earths. For this purpose, we have chosen the system Sr1−xB...
Hypercoordinate transition-metal species are mainly dominated by the 18-valence-electron (18ve) counting. Herein, we report ternary MAl6S6 (M = Ni, Pd, Pt) clusters with the planar hexacoordinate metal (phM) centers, which feature 16ve counting inste...
A survey of theoretical studies of charge transfer involving collisions of multiply-charged ions with atomic neutrals (H and He) is presented. The calculations utilized the quantum-mechanical molecular-orbital close-coupling (MOCC) approach where the...
Here, we report the hydrothermal synthesis of BFO (bismuth ferrite) and Bi1−xAgxFeO3 (x = 0.01, 0.02) ultrafine nanopowders. The diffraction patterns show that all obtained particles belong to the R3c space group. On top of that, crystal struct...
In 1991 the layered organic compound κ-(BEDT-TTF)2Cu2(CN)3 with a triangular lattice was synthesized for the first time. Although, originally, the focus was on the superconducting properties under pressure, this frustrated Mott insulator has be...
Chemical bonding is the stabilization of a molecular system by charge- and spin-reorganization processes in chemical reactions. These processes are said to be local, because the number of atoms involved is very small. With multi-configurational self-...
Histamine levels in the human brain are controlled by rather peculiar metabolic pathways. In the first step, histamine is enzymatically methylated at its imidazole Nτ atom, and the produced N-methylhistamine undergoes an oxidative deamination cat...
As part of a systematic study on the structures of the mixed halide isothiocyanates, SnIIHal(NCS), their single crystals were grown and structurally characterized. For Hal = F (1), the SnClF structure type was confirmed, while with Hal = Cl (2), Br (...
Monoamine oxidases (MAOs) catalyze the degradation of a very broad range of biogenic and dietary amines including many neurotransmitters in the brain, whose imbalance is extensively linked with the biochemical pathology of various neurological disord...
By following the intrinsic reaction coordinate connecting transition states with energy minima on the potential energy surface, we have determined the reaction steps connecting three-dimensional hexaborane(12) with unknown planar two-dimensional hexa...
As part of an effort to characterize clusters and intermediate phases likely to be encountered along solution reaction pathways that produce iron and aluminum oxide-hydroxides from Fe and Al precursors, the complete structure of Al10O14(OH)2 (akdalai...
Direct wide-bandgap III-Ns and II-Os have recently gained considerable attention due to their unique electrical and chemical properties. These novel semiconductors are being explored to design short-wavelength light-emitting diodes, sensors/biosensor...
Ceria is one of the most important functional rare-earth oxides with wide industrial applications. Its amazing oxygen storage/release capacity is attributed to cerium’s flexible valence conversion between 4+ and 3+. However, there still exists...
The fluorine-adsorption-induced local bond relaxation and valence-energy-state evolution of the Ti(0001) surface were examined through density functional theory calculations. The predicted bond–band–barrier (3 B) correlation notation fram...
Diffusion bonding is an exciting technology expected to open new fields of application. To further develop this technology, it is necessary to investigate the inter-diffusion phenomena that occur at the atomic level at the interface of bonded junctio...
First, we discuss a common feature of single-phase pure metals and amorphous and high-entropy alloys: the maximum value of hardness corresponding to a valence electron count (VEC) value of around 6.5–7. This correlation is explained by the coin...
A method for generally predicting interface chemical bonding at the metal–oxide interface with the interface reaction considered is reported. So far, the interface between pure metal or alloy and 11 oxides—MgO, Al2O3, SiO2, Cr2O3, ZnO, Ga...
Understanding the bonding nature of solids is decisive, as knowledge of the bonding situation for any given material provides valuable information about its structural preferences and physical properties. Although solid-state tellurides are at the fo...
Rare-earth-doped mixed crystals have demonstrated tunable optical properties, and it is of great importance to study the structural characteristics of the mixed-crystal hosts. Herein, LuxGd1-xVO4 (0 ≤ x ≤ 1) solid solution nanocrystals were syn...
A topological index as a graph parameter was obtained mathematically from the graph’s topological structure. These indices are useful for measuring the various chemical characteristics of chemical compounds in the chemical graph theory. The num...
An improved understanding of the correlation between the electronic properties of Mn-O bonds, activity and stability of electro-catalysts for the oxygen evolution reaction (OER) is of great importance for an improved catalyst design. Here, an in-dept...
Understanding the electronic nature of materials’ compressibility has alwaysbeen a major issue behind tabulation and rationalization of bulk moduli. This is especiallybecause this understanding is one of the main approaches to the design and proposal...
Ceramic samples of CuCr1−xYxO2 (x = 0–0.02) were synthesized via the high temperature solid-state reaction method, and the influence of Y3+ doping on their microstructure and antiferromagnetic phase transitions was systematically investig...
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