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Numerical results for ground-state and excited-state properties (energies, double occupancies, and Matsubara-axis self-energies) of the single-orbital Hubbard model on a two-dimensional square lattice are presented, in order to provide an assessment of our ability to compute accurate results in the thermodynamic limit. Many methods are employed, including auxiliary-field quantum Monte Carlo, bare and bold-line diagrammatic Monte Carlo, method of dual fermions, density matrix embedding theory, density matrix renormalization group, dynamical cluster approximation, diffusion Monte Carlo within a fixed-node approximation, unrestricted coupled cluster theory, and multireference projected Hartree-Fock methods. Comparison of results obtained by different methods allows for the identification of uncertainties and systematic errors. The importance of extrapolation to converged thermodynamic-limit values is emphasized. Cases where agreement between different methods is obtained establish benchmark results that may be useful in the validation of new approaches and the improvement of existing methods.

Chromium‐doped α‐Fe2O3 samples are successfully synthesized by using a ball‐milling‐assisted rheological phase method combined with heat treatment. The electronic properties of undoped α‐Fe2O3 and 4.0 at % Cr‐doped α‐Fe2O3 are investigated by first‐principles calculations. The calculation results show that Cr doping can reduce the band gap and impurity levels that appear in the band gap. The structure and morphology of the samples are evaluated by X‐ray diffraction, field‐emission scanning electron microscopy, and high‐resolution transmission electron microscopy. The Cr‐doped α‐Fe2O3 electrode delivers a higher reversible capacity and outstanding rate capability as the anode of a lithium‐ion battery compared with the undoped α‐Fe2O3 electrode. The initial discharge/charge capacities of the 4.0 at % Cr‐doped α‐Fe2O3 electrode can reach 1624/1065.9 mAh g−1, respectively, and exhibit an excellent reversible capacity of 971.3 mAh g−1 after 150 cycles at a current density of 0.1 A g−1. Even after 200 cycles, the capacity can remain as high as 758.1 mAh g−1 at a current density of 0.5 A g−1, far beyond than that of the undoped α‐Fe2O3 electrode (376.5 mAh g−1). The forbidden fruit: For Cr‐doped α‐Fe2O3 and undoped α‐Fe2O3, the calculated band gap is 1.82 and 1.90 eV, respectively. The appearance of impurity levels in the forbidden band can be observed, which can convert photons into electron‐hole pairs below the band gap energy. The decrease in the band gap and the appearance of impurity levels in the band gap indicate that the increase in conductivity is an important factor in improving the cycle stability of the Cr‐doped α‐Fe2O3 electrodes. [ABSTRACT FROM AUTHOR]

Mn3+ and Bi3+ co-doped Y6WO12 samples with hexagonal structure were synthesized via an improved salt pyrogenation method at a temperature region of 700-1100 °C for 3 h. In Y6WO12, Mn3+, substituting Y3+, occupies a seven-coordination site and its energy levels are treated in near Oh symmetry. The samples doped by Mn3+ alone emit the most intensive blue light at 420 nm under excitation at 247 nm due to charge transition (CT). The mechanism of sensitization of Bi3+ for Y6WO12:Mn3+ was also analyzed by taking account of metal-to-metal charge-transfer (MMCT) from Bi3+ to Mn3+. As a consequence, the phosphor Y6WO12:Mn3+/Bi3+ can emit blue light under radiation of 370 nm, and the emission intensity is enhanced about five times by the sensitizer Bi3+. The optimal doping concentration of Bi3+ is determined as 1 at% for the emission at 420 nm in Y6WO12:0.5 at% Mn3+ phosphors. [ABSTRACT FROM AUTHOR]

A new dinuclear complex of formula [Co2(dien)2(dmg)2]⋅(ClO4)2⋅4.5H2O (dien = diethlyenetriamine, dmg2− = dianion of dimethylglyoxime) has been synthesized and characterized by single crystal X-ray diffraction analysis. It crystallizes in the monoclinic space group c2/ c, with a = 20.868(7) Å, b = 11.408(4) Å, c = 15.816(4) Å, β = 116.97(2)○, V = 3355.8(17) Å3, Z = 4, F(000) = 1732. The structure consists of a dmg2−-bridged Co(III) dimer. The coordination environments of two Co(III) ions are identical. Each cobalt(III) ion is coordinated by five nitrogen of one dien molecule and one dmg2− ligand, and the coordination sphere is completed by an oxygen atom of the bridging dmg2−. The compound is characterized by means of room temperature magnetic susceptibility measurement and infrared spectroscopy. [ABSTRACT FROM AUTHOR]

A novel copper complex polymer {[Cu4(dmg)2(Hdmg)2(H2dmg)2(H2O)2](ClO4)2}∞ (H2dmg=dimethylglyoxime) has been synthesized and its structure was determined by X-ray single crystal diffraction methods. The complex polymer is like a 1D infinite chain with topological type as a sequence of fused rings connected by out-planar Cu&z.sbnd;O bonds, in which oximato groups (&z.dbnd6;N&z.sbnd;O−) act as two-dentate bridges to link center Cu2+ cations. This structure shows that oximes have great perspective in coordination chemistry and supramolecular polymer chemistry. Molecular structure and spectroscopic properties of the polymer complex were discussed in the article. [Copyright &y& Elsevier]

The mol­ecule of the title trinuclear cadmium(II) complex, [Cd3Cl6(atrz)6] (atrz = 4-amino-1,2,4-triazole, C2H4N4), has a threefold axis of symmetry with three Cd atoms located on the threefold axis. The atrz ligands bridge neighbouring Cd atoms to form the trinuclear complex. [ABSTRACT FROM AUTHOR]

Distal humerus type C fracture is a rare and complicated intra-articular injury. Non-surgical treatment is difficult to achieve accurately reduction and reconstruction of articular surface, while open reduction and internal fixation is the best treatment option. Olecranon osteotomy could provide adequate surgical exposure, and is the most commonly used surgical method, but complications such as non-union osteotomy, internal fixation failure occurred. To avoid sacrificing integrity of olecranon, paratricipital approach, triceps reflecting approach, triceps reflectin ganconeus pedicle approach, triceps splitting and triceps tongue-shaped flap approach have been applied to fracture revealed. However, there is a certain contradiction of choice between surgical exposure and extension function of elbow due to limitations of different approaches. With the promotion of "double-column" theory, double plates has significant mechanical advantages over single plates. Even if parallel double-plate has more advantageous than vertical double-plate in vitro biomechanical experiments, it is not clear whether there is any difference between two methods in clinical application. Elbow arthroplasty may be the final choice for C-type fractures that could not be reconstructed on articular surface, but its long-term efficacy remains to be observed due to technical limitations., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© 2018 by the China Journal of Orthopaedics and Traumatology Press.)

The title compound, [Cd(C(4)H(4)O(4))(H(2)O)(2)](n), has been synthesized under hydro-thermal conditions. The asymmetric unit consists of one Cd(2+) cation, one succinate anion and two aqua ligands. The Cd atoms present a distorted penta-gonal bipyramidal coordination and are bridged into layers parallel to (201) by succinate ligands.