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71.
72.
Gary W. Schnuelle S. Swaminathan David L. Beveridge 《Theoretical chemistry accounts》1978,48(1):17-27
A theoretical study of ion hydration using the statistical thermodynamic supermolecule-continuum method is described. The cell and shell methods are used for configurational averaging. Enthalpies, free energies and entropies are calculated for Li+, Na+, K+, F– and Cl– each four coordinated with water. The results are in reasonable accord with experiment. A comparison of the site method, cell method and shell method results is presented. The supermolecule-continuum approach to solvent effects seems to be capable of accommodating essential features for the calculation of solvation energy and solvent effects on structure and properties. 相似文献
73.
Turevskaya E.P. Berdyev D.V. Turova N.Ya. 《Journal of Sol-Gel Science and Technology》1997,8(1-3):111-115
Complex formation in solutions of barium and zirconium alkoxides in ROH (R=i-Pr, Et) was studied. A number of bimetallic complexes were isolated, and their structure and properties were studied. The
sol-gel method yields a single-phase BaZrO3 powder only wheni-PrOH solutions of the alkoxides are used. In this case, the oxocomplex, BaZrO(OPr-i)4.(1–2)i-PrOH, is the precursor of the mixed oxide. 相似文献
74.
A.A. FilaretovM.G. Zhizhin L.N. KomissarovaV.P. Danilov V.V. ChernyshevB.I. Lazoryak 《Journal of solid state chemistry》2002,166(2):362-368
A new ammonium indium phosphate (NH4)In(OH)PO4 was prepared by hydrothermal reaction in the In2O3-NH4H2PO4-NH3/OH system (T=200°C, autogenous pressure, 7 days). The formula (NH4)In(OH)PO4 was determined on the basis of chemical and thermal analysis (TG/DSC), X-ray powder diffraction and IR-spectroscopy. (NH4)In(OH)PO4 crystallizes in the tetragonal system with space group P43212 (No. 96); a=9.4232(1) Å, c=11.1766(1) Å, V=992.45(2) Å3; Z=8. The crystal structure was refined by the Rietveld method (Rw=6.35%, Rp=5.10%). The second-harmonic generation study confirmed that structure of (NH4)In(OH)PO4 does not have a center of symmetry. The cis-InO4(OH)2 octahedra form helical chains, parallel to the c-axis. The In-O-In bonds are nearly equidistant. The chains are interconnected by phosphate tetrahedra and create tunnels containing the NH4+ ions along the c-axis. (NH4)In(OH)PO4 is isostructural with RbIn(OH)PO4. 相似文献
75.
76.
严继民 《中国科学B辑(英文版)》1990,(7)
An ab initio calculation of the hydrogen bond complex (HF)_2 is given with the 6-311 G~(**) basis set, according to which the potential surface around the balance point of the distancès and the orientations between two HF molecules is obtained. The atomic charges in the system are calculated with the PD/LSF method (potential-derived/least-square-fitting method) and then an analysis of the hydrogen bond interaction between two HF molecules is given with the (exp-6-1) potential function, by means of which it is shown that the main interaction between them is not an electro-static but a charge transfer one. The potential curve between two HF molecules is like a Morse function. 相似文献
77.
根据在自由基引发剂存在下,8,9-苯并-2-亚甲基-1,4,6-三氧螺(4,4)壬烷(Ⅰ)可能存在的竞争反应,推导了动力学方程式。用红外光谱法测定了单体的消失速率和苯酞的生成速率。实验结果与推导动力学方程式相符。进一步证明了单体(Ⅰ)的增长反应由加成聚合和开环—异构化—加成这两个反应组成。这两个反应对总速率的相对贡献与单体浓度有关。得到了共聚物的结构。 相似文献
78.
Numerical results for the ground state of the HN
2
+
and HCO+ molecular ions at their near equilibrium geometry, obtained by the complex molecular orbitals (CMO) method in the extended basis set, are reported. The CMO wavefunction of the HN
2
+
ion is compared with the CI wavefunction obtained in the same basis set. This reveals the nature of approximations inherent in the CMO method. A peculiar feature of the occupation numbers of the CMO natural orbitals is also explained.Alexander von Humboldt Fellow. On leave from the Institute Rudjer Bokovi, Zagreb, Croatia, Yugoslavia. 相似文献
79.
This paper presents in detail a robust, efficient and accurate methodology for the computation of equilibrium composition in gaseous mixtures. The methodology is founded on the concept of the chemical basis, which is defined and formalized using a powerful matricial approach. The method is specially designed to be general, thus providing basic thermodynamic data in several areas, such as combustion, plasma chemistry and, more generally speaking, computational fluid dynamics. The performance of the method is given in terms of CPU usage and the computed results are compared with those in the published literature. The method is shown to yield results of very high quality in terms of accuracy and smoothness. 相似文献
80.
Peter D. Dacre 《Theoretical chemistry accounts》1976,43(2):197-205
The direct CI method, which avoids explicit calculation of the Hamiltonian matrix, is presented in a new form. The method is linked with Davidson's algorithm for iterative evaluation of the ground state eigenvector. The viability of the method is indicated by the test calculations on water which are described. 相似文献