ChemInform Abstract: Correlation Between the Electronic Structure,Effective Mass and Thermoelectric Properties of Rare Earth Tellurides Ba2MYTe5 (M: Ga,In).

The electronic structure, electronic charge density, and band gaps of Ba₂MYTe₅ (M: Ga, In) single crystals are simulated using the full potential linearized augmented plane wave package WIEN2k.     

ChemInform Abstract: Oxidation State 10 Exists.

DFT electronic structure calculations indicate the existence of oxidation state 10 in the T_d structure of PtO₄²⁺.     

ChemInform Abstract: First-Principles Study of Defective and Nonstoichiometric Sr2FeMoO6.

The influence of disorder and stoichiometry-breaking point defects on the structural and magnetic properties of Sr₂FeMoO₆ is studied by electronic structure calculations within the spin-polarized GGA+U approach.     

ChemInform Abstract: Syntheses,Structures, Physical Properties,and Electronic Structures of Ba2MLnTe5 (M: Ga and Ln: Sm,Gd, Dy,Er, Y; M: In and Ln: Ce,Nd, Sm,Gd, Dy,Er, Y).

The title compounds are synthesized by solid state reactions of BaTe, Ga₂Te₃ or In₂Te₃, Ln, and Te (1273—1323 K, 20—48 h) and characterized by single crystal XRD, diffuse reflectance spectroscopy, magnetic susceptibility measurements, second harmonic generation measurements, and DFT electronic structure calculations.     

ChemInform Abstract: Polymorph Engineering of TiO2: Demonstrating How Absolute Reference Potentials Are Determined by Local Coordination.

A multiscale quantum‐chemical approach is used for examining the electronic structure of eight known TiO₂ polymorphs and aligning their ionization potential and electron affinity relative to an absolute energy reference.     

ChemInform Abstract: Effect of Cation Ordering on the Electronic and Lattice Dynamic Properties of Ag2CdGeS4 Polytypes: First‐Principle Calculation.

Theoretical results obtained for three Ag₂CdGeS₄ polytypes (two of space group Pna2₁, one of Pmn2₁) show the effects of cation arrangement on the electronic and lattice dynamic properties such as bonding strength, band structure, and IR spectrum.     

ChemInform Abstract: Electronic Structure,Elastic Anisotropy,Thermal Conductivity and Optical Properties of Calcium Apatite Ca5(PO4)3X (X: F,Cl or Br).

The structural properties, phase stability, electronic structure, elastic properties, and optical properties of Ca₅(PO₃)₄F (FA), Ca₅(PO₃)₄Cl (ClA) and Ca₅(PO₃)₄Br (BrA) are studied by DFT calculations with the generalized gradient approximation.     

ChemInform Abstract: An 18‐Electron System Containing a Superheavy Element: Theoretical Studies of Sg@Au12.

With reference to the high‐symmetric structure and significant stability of M@Au₁₂ cage molecules (M = group 6 transition element), the geometric and electronic structures as well as bonding of various Sg@Au₁₂ isomers are investigated by DFT (PW91, PBE, B3LYP) and wave function theory (MP2, CCSD(T)) approaches.     

The molecular and electronic structure of dibenzo[g,p]chrysene: A twisted case

Summary Studies of the electronic structure and spectrum of dibenzo [g,p]chrysene, carried out in 1965 and 1985, were not fully conclusive. They are repeated here by means of improved linear dichroism spectroscopy, quantum mechanical calculations of the spectra, and structural studies. Based on the new evidence, especially the observed transition moment directions, it is concluded that the molecule is nonplanar with D₂ symmetry. The experimentally determined transition moment directions also allow a complete assignment of all significant transitions in the region 25 000 to 45 000 cm^–1. All three possible (perpendicular) transition moment directions are represented among the observed electronic transitions.Dedicated to Jan Linderberg on the occasion of his 60th birthday     

Simulation of the structure of some silicon carbide clusters by the MNDO method

Simulations of the geometric and electronic structure of C₄₄, C₄₅, Si₄₅, C₄₀Si₅, and C₄₄Si clusters were performed by the MNDO method. The geometries of the filled clusters, calculated by the MM2 method, were used as initial approximations. It was found that the filled clusters C₄₅ and C₄₄Si are transformed into endohedral clusters X@C₄₄ (X-C or Si, respectively) after energy optimization. The highest occupied energy level of the HOMO of the filled tetrahedral cluster Si₄₅ ofT symmetry is triply degenerate and is only occupied by four electrons. The structure of Si₄₅ ²⁻ dianion ofT symmetry was calculated. Two filled structures for the C₄₀Si₅ cluster were found. The coordination numbers of the central Si atom in these structures are 4 and 3, respectively. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 54–56, January, 1997.     

ChemInform Abstract: Scaffolding,Ladders, Chains,and Rare Ferrimagnetism in Intermetallic Borides: Electronic Structure Calculations and Magnetic Ordering.

The electronic structures of “Ti_9‐nFe_2+nRu₁₈B₈” (n = 0, 0.5, 1, 2, 3), including the recently synthesized compounds Ti_9‐nFe_2+nRu₁₈B₈ (n = 1, 2), are determined by TB‐LMTO‐ASA computations.     

Electrochemical Survey: The Effect of the Cage Size and Structure on the Electronic Structures of a Series of Ytterbium Metallofullerenes

The electrochemical properties of a series of metallofullerenes with different cages, namely, Yb@C₇₄(II), Yb@C₇₆(I, II), Yb@C₇₈, Yb@C₈₀, Yb@C₈₂(I, II, III), and Yb@C₈₄(II, III, IV), have been systematically investigated by cyclic and differential pulse voltammetry experiments for the first time. This article discusses the electronic structures of these metallofullerenes based on the results from these experiments. From previous electrochemical work and the above discussion, it is concluded that the nondegenerate LUMO is a common characteristic of the electronic structures of the higher fullerenes and monometallofullerenes. In addition, the effect of the cage on the electronic structure and properties of the metallofullerene is estimated from the plot of the reduction potential versus the carbon number of the metallofullerene. This estimation shows that usually the electronic structure and properties of the metallofullerene vary with cage size and structure. The cage structure is of particular importance for determining the electronic structure and properties. Moreover, an explanation concerning the abundance and stability of C₈₂‐based trivalent monometallofullerenes is given from an electronic structural standpoint.     

W6Cl18: Neue Synthesen,neue Strukturverfeinerung,elektronische Struktur und Magnetismus

W₆Cl₁₈: New Syntheses, New Structure Refinement, Electronic Structure, and Magnetism Pure W₆Cl₁₈ was synthesized after two methods, by oxidizing W₆Cl₁₂ with CCl₄ in an autoclave, and by reaction of W₆Cl₁₂ in a chlorine gas flow. At temperatures above 400 °C and under atmospheric pressure W₆Cl₁₈ transforms into W₆Cl₁₂. The crystal structure of W₆Cl₁₈ was refined after the Rietveld method on X‐ray powder data. The unusual electronic conditions of the 18 electron cluster [W₆Cl₁₂]Cl₆ are compared with those of the electron‐precise 24 electron cluster [W₆Cl₈]Cl₄. The compound exhibits paramagnetic behaviour with two electrons in antibonding energy levels.     

Protein Unfolding: 1H‐NMR Studies of Paramagnetic Ferricytochrome c‐550 from Horse Heart

Electronic transfer protein cytochrome c‐550 from horse heart is studied in the unfolded state by means of paramagnetic ¹H NMR. The protein contains 104 aminoacid residues and a heme group with low spin Fe^III ion in the oxidized form of protein. The global secondary structure is of the α‐helix type as occurs in the case of very other cytochromes c investigated such as cyt c‐550 from Thiobacillus versutus or cyt c‐551 from Pseudomonas aeruginosa. We have studied the coordination characteristic and electronic properties of heme iron horse heart ferricytochrome c‐550 at increasing denaturing conditions (up to 3.1 M GuHCl and 288‐323 K). The ¹H T₁ values of the signals were measured and some resonance assignments made based on EXSY experiments. The electronic structure of the iron(III) is discussed on the basis of the temperature dependence of the isotropic shifts and relaxation times. These results show that it is produced a change of spin, from low‐spin iron(III) (²T₂, S=1/2) in the folded state to high‐spin iron(III) (⁶A₁, S=5/2) in the unfolded state. It seems to be possible that in the opened structure the ferricyt c‐550 loses one axial ligand (His/‐) appearing the spin transition.     

A Computer Simulation of the Electronic Structure of Leucine in Aqueous Solution

In order to obtain the electronic structure of leucine (Leu) in aqueous solution, we studied three systems: Leu+7H₂O, Leu+8H₂O and Leu+9H₂O. The results indicated that the system Leu+8H₂O was the only choice which was both acceptable and doable: its computational effort was affordable, and it could simulate a main part of the solvent effect on the electronic structure of Leu in solution. Based on the system Leu+8H₂O, all-electron, ab initio calculations were performed to construct an equivalent potential of water for the electronic structure of Leu with dipoles. The results showed that the main effect of water on the electronic structure of Leu was raising the occupied states about 0.0824 Ry on average, and broadening the energy gap by 11%. The water effect on the electronic structure of Leu could be well simulated by the dipole potential. The obtained equivalent potential can be applied directly to the electronic structure calculation of proteins in solution.     

A fantastic graphitic carbon nitride (g-C3N4) material: Electronic structure,photocatalytic and photoelectronic properties

As an analog of graphite, graphitic carbon nitride (g-C₃N₄) has been the hotspot in the materials science for its unique electronic structure. With medium band gap as well as thermal and chemical stability in ambient environment, it becomes one of the most promising photocatalytic materials. Intensive investigation has been focus on its photocatalytic performance for various reactions to date. What is more, controllable modulation of its electronic structure via doping or chemical functionalization is available. In addition, considerable attention has been paid on its photoelectronic application, such as light emitting device, photocathode, optical sensor, etc. Based on the electronic properties and pathway to modulate its electronic structure, in this review, we highlight the applications of g-C₃N₄ ranging from photocatalytic to photoelectronic materials.     

ChemInform Abstract: Superhalogens as Building Blocks of Halogen-Free Electrolytes in Lithium-Ion Batteries.

In the search for halogen-free electrolytes, the electronic structure of current electrolytes is studied via DFT-based first-principles calculations of the ground state geometries and total energies of anionic BF₄^-, PF₆^-, AsF₆^-, FePO₄^-, ClO₄^-, N(SO₂F)₂^-, and N(SO₂F₃)₂^-.