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1.
The crystal structures of single crystals of YCo3+.36Co2+.32Pt4+.32O3 and DyCo3+.36Co2+.32Pt4+.32O3 have been examined at room temperature, and shown to be isostructural with GdFeO3, which belongs to space group Pbnm. The overall expansion of octahedra caused by substitution of platinum enhances the distortion of rare-earth dodecahedra by moving 4 out of 12 oxygens further away from the rare-earth ions, as shown by the rotation of octahedra along the [110] axis. No order has been found for Co2+, Co3+, and Pt4+.  相似文献   

2.
The energies, equilibrium geometries and harmonic frequencies of the three electronic states (the ground state X 1Σ+, the first excitation state A 1Σ+ and the second excitation degenerate state B 1Π) of LiH molecule have been calculated by using the GSUM (Group Sum of Operators) method of SAC/ SAC-CI with the basis sets D95(d), 6-311G**, and cc-PVTZ. Comparing with the above-mentioned three basis sets, the conclusion is gained that the basis set D95(d) is the most suitable for the energy calculation of LiH molecule. The whole potential curves for these three electronic states are further scanned, using SAC/D95(d) method for the ground state and SAC-CI/D95(d) methods for the excited states. Murrell-Sorbie function were fitted using a least square and then the spectroscopy constants are calculated, which are in good agreement with the experimental data.  相似文献   

3.
BH分子X 1Σ+、A 1Π和B 1Σ+ 态的势能函数   总被引:1,自引:0,他引:1  
利用SAC/SAC-CI方法,使用D95++、6-311++g及cc-PVTZ等基组,对BH分子的基态(X 1Σ+)、第一简并激发态(A 1Π)及第二激发态(B 1Σ+)的平衡结构和谐振频率进行了优化计算. 通过对三个基组计算结果的比较,得出了cc-PVTZ基组为三个基组中的最优基组的结论;使用cc-PVTZ基组,利用SAC的GSUM(group sum of operators)方法对基态(X 1Σ+), SAC-CI的GSUM方法对激发态(A 1ΠB 1Σ+)进行单点能扫描计算, 用正规方程组拟合Murrell-Sorbie函数,得到了相应电子态的完整势能函数;从得到的势能函数计算了与基态(X 1Σ+)、第一简并的激发态(A 1Π)和第二激发态(X 1Σ+)相对应的光谱常数(Be、αe、ωe 和ωeχe),结果与实验数据较为一致. 其中基态、第一激发态与实验数据吻合得较好.  相似文献   

4.
The liquid–liquid equilibrium data at 25 °C of the system water–1-pentanol–1-propanol, that present a I type solubility gap, have been used to calculate the spinodal curve of this system through the use of the Wheeler–Widom model. As in the case of the water–chloroform–acetic acid system, analyzed with the same model in the past, a local fitting method has been necessary. A procedure based on the experimental position of the plait point was used to obtain the single spinodal points. The relative positions of binodal and spinodal curves indicate the presence of a large metastable area in the alcoholic-rich region.  相似文献   

5.
《Chemical physics》1987,112(1):139-146
The electric dipole moment of the excited B1+ (υ′ = 0) state of MgO produced in a gas-phase reaction of Mg(1S) atoms and N2O is measured using the technique of Stark quantum-beat spectroscopy. It is shown to be |μυ′=0| = 5.94(24) D. The lifetime of the excited B1+ (υ′ = 0) state is determined as τ = 22.5(1.5) ns. Using laser excitation spectroscopy and by direct observation of the P(1) line splitting at high electric field strengths in the B1+−X1+ (0,0) system the ground state electric dipole moment is measured yielding |μυ=0| = 6.2(6) D. Furthermore an electric-field-induced Q branch is observed.  相似文献   

6.
《Chemical physics letters》1985,119(6):477-479
New visible emission systems have been observed from the helium afterglow reaction of SnH4. On the basis of the rotational analysis, they were interpreted as the a3Π0-X1Σ+ and a3Π1-X1Σ+ subsystems of SnH+. Spectroscopic constants have been obtained for the a3Π0+ and X1Σ+ states.  相似文献   

7.
The vibrational and rotational molecular constants have been determined for the A1Σ+  X1Σ+ system of the isotopic potassium hydrides: KH and KD. From these experimental term values, isotopically combined PMO-RKR-van der Waals potentials are constructed, which are checked by direct integration of radial Schrödinger equation. As an additional check on the accuracy of the potentials, the wavefunctions were used to compute Bν, Dν, Hν and Lν values. The agreement between the calculated and experimental results is quite satisfactory. Franck-Condon overlap integrals and probability density distributions have been calculated. The anomalous behaviour of the A1Σ+ state may be observed in the probability density functions of the lowest vibrational levels.  相似文献   

8.
《Chemical physics》1987,117(1):149-162
The molecular constants of the A1Σ+ and X1Σ+ states of the KH and KD molecules have been determined using mass relations correspondent to a normal isotope shift. For the calculation we have used data of the laser-induced fluorescence spectrum by the Ar+ 4881 Å exciting line photographed in our laboratory, as well as previous data presented by other authors. From the spectroscopic terms, quantum-mechanical PMO-RKR-van der Waals hybrid potentials have been generated. Numerical calculations for the A1Σ+ and X1Σ+ states of the KH and KD species are comapred with quantum-mechanical values obtained by numerical solution of the radial Schrödinger equation. Vibrational wavefunctions appropriate to the potential curves yield values of Eυ and Bυ which are in close agreement with the experimental results. The probability distribution functions and Franck-Condon factors for the A1Σ+ ↔ X1Σ+ band system have also been determined. It is observed that the anomalous behaviour of the A state is clearly revealed with a changed anharmonicity for the lowest vibrational levels.  相似文献   

9.
The thermal behaviour of chemically deintercalated samples obtained by HCl treatment of non-stoichiometric Li/Ni mixed oxides is studied. A multi-step reduction of Ni with O2 evolution is observed between room temperature and 800C. Two cation redistribution processes are shown by the exothermal occurrence of a spinel phase at 300C and the endothermal reduction to a rock-salt phase with random distribution of Li and Ni cations in octahedral sites at 800C.The authors wish to express their acknowledgement to CICYT and PFPI for financial support.  相似文献   

10.
11.
利用SAC/SAC-CI方法,使用D95++、6-311++g及cc-PVTZ等基组,对BH分子的基态(X1撞+)、第一简并激发态(A1装)及第二激发态(B1撞+)的平衡结构和谐振频率进行了优化计算.通过对三个基组计算结果的比较,得出了cc-PVTZ基组为三个基组中的最优基组的结论;使用cc-PVTZ基组,利用SAC的GSUM(groupsumofoperators)方法对基态(X1撞+),SAC-CI的GSUM方法对激发态(A1装和B1撞+)进行单点能扫描计算,用正规方程组拟合Murrell-Sorbie函数,得到了相应电子态的完整势能函数;从得到的势能函数计算了与基态(X1撞+)、第一简并的激发态(A1装)和第二激发态(B1撞+)相对应的光谱常数(Be、琢e、棕e和棕e字e),结果与实验数据较为一致.其中基态、第一激发态与实验数据吻合得较好.  相似文献   

12.
From the spectroscopic experimental data available in the literature we have determined the mass-reduced Dunham coefficients for the A1Σ+X1Σ+ system of the isotopic species CsH and CsD. Based upon these results, for both ground and excited states of cesium hydride and deuteride we report new hybrid rotationless potential energy curves (PMO-RKR-van der Waals) up to the dissociation. As a consistency check on the accuracy of the potentials the eigenvalues were calculated by direct numerical integration of the radial Schrödinger equation and found to agree within the rms error 0.39 cm−1 (X1Σ+) and 0.41 cm−1 (A1Σ+) with the experimental vibrational energies. From the wavefunctions, the rotational constants Bυ, centrifugal distortion terms Dυ, Hυ and Lυ, Franck—Condon factors, and probability density distributions were obtained. The probability density distributions for the lowest vibrational levels of the A1Σ+ show an anharmonicity associated with the anomalous behavior of that state.  相似文献   

13.
《Fluid Phase Equilibria》1999,155(1):95-105
Liquid–liquid equilibrium phase diagrams for two binary systems: water+1-pentanol and water+2-methyl-2-butanol and two ternary systems: water+1-pentanol+2-butyloxyethanol and water+2-methyl-2-butanol+2-butyloxyethanol at 20°C and 30°C are presented in this paper. The experimental results were correlated with the UNIQUAC model by fitting the effective UNIQUAC binary interaction parameters as a function of temperature. Agreement between the calculated and experimental data was very good.  相似文献   

14.
基于民族地区师范生基础薄弱和特殊需求,结合本院的实际情况,构建了"5+2+1"化学实验教学体系。  相似文献   

15.
Thermodynamic properties of quaternary aqueous solutions of mixed chlorides of 1-1*1-1*2-1 charge type with the cations (Na+, NH4 +; Mg2+, Ca2+, Ba2+) were determined using the hygrometric method. The quaternary systems NH4Cl + NaCl + MgCl2 + H2O, NH4Cl + NaCl + CaCl2+ H2O, and NH4Cl + NaCl + BaCl2 + H2O have been studied at 25 °C. The water activities were measured at total molalities from 0.44 mol⋅kg−1 to saturation for different ionic-strength fractions y of NH4Cl, y=(0.20,0.50,0.80), and different ionic strength ratios z for other solutes, z=(0.20,0.50 and 0.80) for each value of y. The obtained data allows the calculation of osmotic coefficients.  相似文献   

16.
A type (ΔKa = 0) rovibrational lines of the near-prolate asymmetric top 16O14N35Cl have been assigned on high resolution Fourier transform spectra: 820 lines of the ν1 band, centered around 1800 cm−1, 435 lines of the ν1 + ν3 band, centered around 2131 cm−1, and 257 lines of the ν2 + ν3 band, centered around 925 cm−1. Least-squares calculations have been carried out over these lines, using the A reduced Watson's hamiltonian in Ir representation; r.m.s. standard deviations of 0.0016 cm−1, 0.0016 cm−1 and 0.006 cm−1 have been respectively obtained, making it possible to measure molecular constants of the (001), (101) and (011) vibrational levels of 16O14N35Cl.  相似文献   

17.
A convenient method for the asymmetric synthesis of 1-amino-alkylphosphonic acids was described.It involved the diastereoselctivealkylation of bicyclic chloromethylphosphonamide derived from(S)-2-ani-linomethylpyrrolidine followed by subsequent conversions leading to aminocompounds by Staudinger method.Acid hydrolysis afforded the targetmolecule in good yield.  相似文献   

18.
4N Baird's rule represented the extension of Hückel's 4N + 2 rule to triplet state systems. In this work we extend the 2(N + 1)(2) Hirsch rule for spherical aromatic species to open-shell spherical compounds and we provide evidence that those spherical species having a same-spin half-filled last energy level with the rest of the levels being fully-filled, i.e., those having 2N(2) + 2N + 1 electrons and S = N + ?, are aromatic.  相似文献   

19.
程铁欣  杨向光  吴越 《化学学报》1995,53(8):781-788
合成了(AO)(ABO3)n(A=La, B=Ni, n-1~4)型系列复合氧化物。用XRD, XPS,IR, TPD, TPR等方法对其进行了表征, 研究了结构特征, 氧化-还原性能。用化学分析方法测定了镍的价态及氧缺陷, 考察了该系列复合氧化物对CO, CH4的完全氧化活性, 并对其活性与化学组成及结构间的关系进行了讨论。  相似文献   

20.
《Fluid Phase Equilibria》2004,216(1):47-52
Isobaric vapor–liquid equilibria for the ternary system 1-propanol+water+lithium chloride has been measured at 100 kPa using a recirculating still. The addition of lithium chloride to the solvent mixture produced an important salting-out effect over the alcohol and the azeotrope tended to be eliminated when the salt content increased, and two immiscible liquid phases were observed in a broad range of salt concentration. The experimental data sets were fitted with the electrolyte NRTL model and the parameters of Mock et al.’s model were estimated. This model has proved to be suitable to represent experimental data in the entire range of compositions. The effect of lithium chloride on the vapor–liquid equilibrium of the propanol+water system has been compared with that produced by other salts.  相似文献   

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