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91.
Effect of screened Coulomb (Yukawa) potentials on the doubly excited meta‐stable bound states and the resonance states with unnatural parities of the helium atom have been investigated in the framework of stabilization method using CI‐type basis functions. A total of 54 resonances (6 each of 1Do and 3Do states, 12 each of 1Fe and 3Fe states, 9 each of 1Go and 3Go states) below the He+(3P) thresholds have been estimated by calculating the density of resonance states using a stabilization method. The resonances belong to the different 3lnl′ (n ≥ 3) series. We have also calculated the doubly excited 1,3Fe and 1,3Go meta‐stable bound states of He atom below the He+ (2P) thresholds. The resonance energies and widths along with the meta‐stable bound states energies are reported for various screening parameters. In free atom case, some of the F‐wave resonance states and most of the cases, F‐ and G‐wave resonance widths are reported for the first time. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008 相似文献
92.
The low-lying electronic states of TlX (X=F, Cl, Br, I, and At) are investigated using the configuration interaction based complete active space third-order perturbation theory [CASPT3(CI)] with spin-orbit coupling accounted for. The potential energy curves and the corresponding spectroscopic constants are reported. The results are grossly in good agreement with the available experimental data. The absorption spectra are simulated as well to reassign the experimental bands. The present results are also useful for guiding future experimental measurements. 相似文献
93.
在组态相互作用模型的基础上对Be2+等二电子系列基态电子关联能的计算方法进行了研究,利用变分原理,采用B样条处理径向基,用“混合L”法处理角向基,给出He,H-,Li+,Be2+,B3+等5种原子(离子)系列的有关计算结果,并与其它理论方法计算的结果作了对比,显示出B样条方法优越的计算能力. 相似文献
94.
Abdullatif Alfutimie A.P. Ormerod J.W. Jones Helen Wheatcroft Douglas J. Edwards 《Liquid crystals》2013,40(8):1169-1178
Chromonic liquid crystals are currently receiving increased attention because they have applications in a wide range of products. In this study, we have compared the chromonic mesophase behaviour of four azo dyes with similar chemical structures. Our objective is to determine if there is an obvious link between mesophase formation and dye chemical structure. Orange G does not form mesophases over the concentration range examined (saturated solution > ~20–30 wt%). The other three compounds all form nematic (N) and hexagonal (H) mesophases, but over very different concentration ranges. X-ray diffraction shows that the ordered Edicol Sunset Yellow (ESY) aggregates present in the mesophases have a single molecule cross section, while those of CI Acid Red have a cross section equivalent to six to eight molecules, probably organised in a ‘water-filled pipes’ structure. NMR quadrupole splittings of 2H2O demonstrate that water binding to the aggregates is similar to that found for surfactant lyotropic mesophases. The sodium (23Na) quadrupole splittings for Orange II and CI Acid Red are similar to the values found for surfactant hexagonal phases, suggesting that most sodium ions are ‘bound’ to the aggregates. This is unlike the behaviour of ESY where only one of the two sodium ions is bound. 相似文献
95.
本文把组态相互作用波函数展开成解析的Slater-型轨道形式,利用程序CIV3计算了SiⅫ的单组态和多组态能级和谐振子强度。结果表明,组态相互作用对能级影响很小,但对谐振子强度的影响却很大。对于初末两态主量子数不同的跃迁,组态相互作用对长度规范下的谐振子强度影响较大;而对于初末两态主量子数相同的跃迁,组态相互作用对速度规范下的谐振子强度影响较大。文中还对产生这种现象的原因进行了讨论,并把我们的结果与实验以及其它理论结果进行了比较。 相似文献
96.
Neutral/zwitterionic form equilibrium, excited state wave functions, absorption and emission spectra of kynurenine (KN) in various solvents (water, methanol, ethanol, and dimethylsulfoxide) have been studied theoretically. The ground electronic state geometries have been optimized by density functional theory methods; the geometries of the first two singlets excited electronic states have been optimized using the CASSCF technique. The influence of the solvent was taken into account by the calculation of the solvation free energies using the Polarizable Continuum Model (PCM). The spectra of electronic absorption and fluorescence emission have been calculated by the CS‐INDO S‐CI and SDT‐CI methods [Momicchioli, Baraldi, and Bruni, Chem Phys, 1983, 82, 229]. The calculated data reproduce the experimental positions of maxima and the solvent‐induced shifts of the absorption and emission bands well. The energy gap between the two lowest excited states of KN increases from aprotic to protic solvents. This fact suggests that the “proximity effect” cannot be responsible for the ultrafast decay of KN fluorescence in protic solvents. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011 相似文献
97.
K. Koc 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,53(1):9-14
Lifetime of 2s22p 2P3/2 level along with fine structure separations for the lowest 2P doublet of boron-like ions, from Z=14 to Z=30 have been calculated using multireference relativistic configuration interaction
(MR RCI) method based on the no-pair Dirac-Coulomb-Breit (DCB) Hamiltonian. Analytic basis sets of Gaussian-type functions
are employed to expand the upper and lower components of the Dirac four-spinors in the matrix Dirac-Fock self-consistent field
(DF SCF) and relativistic MR CI procedures. Error with respect to variation of basis set parameters was estimated. QED corrections
were estimated by evaluation of electron self-energy and vacuum polarisation. 相似文献
98.
99.
田兴时 《原子与分子物理学报》1990,7(2):1458-1462
选择所有单、双电子激发组态及部分三电子激发组态,用CI法计算了N_2第四正带系的振子强度、其值为0.04673,与实验值吻合。 相似文献
100.
Anthony Wu M. Lynn Pearson David L. Shekoski Ricardo J. Soto Richard D. Stewart 《Journal of separation science》1979,2(9):558-562
Studies of the pharmacology and toxicology of the popular insect repellant, N,N-diethyl-m-toluamide (DEET), have largely been done in animal models using radioactive tracing without the structural elucidation of its metabolites. This paper describes a high resolution gas chromatography/mass spectrometry (GC/MS) technique and reports the results of the preliminary characterization of the metabolites of DEET in the urine of a 30-year-old man who had been exposed to DEET contained in a commercial product. The metabolites were extracted and separated with an OV-101 glass capillary column, 30 m × 0.3 mm, and mass spectrometric elucidations were carried out with both Electron Impact (EI) and Chemical Ionization-Methane (MCI) modes. Oxidation of the benzylic moiety and hydroxylation of the sidechain of DEET molecules appeared to be the predominate routes of metabolism in man. The artifacts were also proposed. 相似文献