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Rostov-na-Donu, Russia

Bublikov D.N.,Southern State University
Crystallography Reports | Year: 2011

The combinatorial approach is used to simulate superstructures of the NaCl type. An algorithm for searching for possible models of superstructures is developed which includes alternating the occupation of the metal sublattice by chemically different cations in an isolated cubic fragment. The application of this algorithm to small cubic fragments is demonstrated. The models are compared with known complex metal oxides (binary A-B-O and ternary A-B-C-O compounds). © Pleiades Publishing, Inc., 2011.

Starikov A.G.,Russian Academy of Sciences | Minyaev R.M.,RAS Institute of Chemistry | Starikova A.A.,Southern State University | Minkin V.I.,RAS Institute of Chemistry
Russian Journal of Coordination Chemistry/Koordinatsionnaya Khimiya | Year: 2010

The addition reaction of two pyridine molecules to Ni(II) β-diketonate bis-chelate was studied by quantum chemical density functional theory calculations (B3LYP/6-311++G(d, p)). The addition of the first pyridine molecule to the trans-position was found to be the most favorable channel for this two-stage process; the reaction is accompanied by a change in the spin state of the system. The transition between the potential energy surfaces of different multiplicity occurs at the first stage without considerable energy expenditure; the addition of the second pyridine molecule is barrierless. © Pleiades Publishing, Ltd., 2010.

Ryabova M.V.,Southern State University | Shchekinov Y.A.,Russian Academy of Sciences
Astronomy Reports | Year: 2011

The relationship between the masses and metallicities of galaxies could be non-monotonic, due to the outflow of matter in these systems. It is shown using a simple, one-zone, chemical-dynamicalmodel that the metallicity should be a non-monotonic function of the mass for spheroidal dwarf galaxies with low masses of M ≤ 10 8M ⊙, and a monotonically growing function for galaxies with higher masses. This is consistent with observations. © 2011 Pleiades Publishing, Ltd.

Rodina I.S.,Southern State University | Kravtsova A.N.,Southern State University | Soldatov A.V.,Southern State University
Optics and Spectroscopy (English translation of Optika i Spektroskopiya) | Year: 2011

The local atomic structure of titanium-containing forsterite is investigated based on analysis of X- ray absorption near-edge structure (XANES) spectra. The Ti K-XANES spectra of the mineral under study are calculated for several possible structural models. Theoretical analysis of the X-ray absorption spectra is performed based on the full-potential finite-difference method. The local geometry of the titanium environ- ment is determined by comparing the experimental Ti K-XANES spectrum with the theoretical spectra cal- culated for different structural models. The structural model where titanium atoms substitute for silicon ones is found to be most likely for titanium-containing forsterite. The calculated partial densities of electron states of titanium near the bottom of the conduction band of titanium-containing forsterite are analyzed. © Pleiades Publishing, Ltd., 2011.

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