Combined analysis of the PFOODR data on the a 3Σ u+ , 23Πg, 23Σ g+ , 33Πg, and 43Σ g+ states of the K2 molecule

The known and new heterogeneous spectral data on the triplet states a ³Σ _u ⁺ , 2³Π_g, 2³Σ _g ⁺ , 3³Π_g, and 4³Σ _g ⁺ of the K₂ dimer are simultaneously fitted. The data published in J. Mol. Spectrosc. 234, 41 (2005) are refined. The new information used in the analysis contains the data on the 2³Σ _g ⁺ state, which have not been considered previously. The range of internuclear distances where the potential function of the lowest triplet state a ³Σ _u ⁺ is defined is extended. Original Russian Text ? V.B. Sovkov, V.S. Ivanov, D. Li, F. Xie, Li Li, 2007, published in Optika i Spektroskopiya, 2007, Vol. 103, No. 5, pp. 747–751.     

The A-X system of Br2+ radical cations

The ²Π_u-X²Π_g transition in Br₂⁺ was reexamined using dispersed laser-induced fluorescence, and emission spectroscopy in a seeded molecular beam. New constants are derived, confirming the large difference between $\text{A}{}^2\text{Π}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ and $\text{A}{}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$, and reconciling the emission spectrum with photoelectron data.     

H2(X1∑g+)—H2(E1∑g+)系统的相互作用

采用显含电子对相关坐标的波函数,在微扰论的框架下计算了E^l∑_g⁺态氢分子与基态氢分子取cross构型时的中长程相互作用。结果表明,该相互作用在分子间距6.5α₀附近存在着一个活化能势垒,在4.5α₀附近显示出较强的化学键行为。 关键词：     

Rotational cooling efficiency upon molecular ionization: the case of Li2(a3Σu+) and Li2+(X2Σg+) interacting with 4He

The low-temperature (up to about 100 K) collisional (de)excitation cross sections are computed using the full coupled-channel (CC) quantum dynamics for both Li₂ and Li₂ ⁺ molecular targets in collision with ⁴He. The interaction forces are obtained from fairly accurate ab initio calculations and the corresponding pseudo-rates are also computed. The results show surprising similarities between sizes of inelastic flux distributions within final states in both systems and the findings are connected with the structural change in the molecular rotor features when the neutral species is replaced by its ionic counterpart.     

The lifetime of the 2pπu → 1sσg transition of the F2+ center in KCl

The lifetime of the 2pπ_u → 1sσ_g transition for the F₂⁺ center in KCl has been measured (15.8 ± 0.7 ns at 8 K) and found to be constant over the temperature range (8–90 K) investigated. No contradiction is found with the Aegerter and Lüty quantum yield data. A forecast for the lifetime of the 2pσ_u → 1sσ_g transition is also made, within the framework of the H₂⁺ model for the F₂⁺ center in alkali halides.     

Vibronic intensity distribution in the B0u-X0g and B1u-X1g transition of Se2

The B0_u⁺-X0_g⁺ and B1_u-X1_g transitions of ⁸⁰Se₂ and ⁷⁸Se₂ are reinvestigated. Several new bands are reported, especially for the B1_u-X1_g system, their vibrational numbering being confirmed by isotope shift studies. The Franck-Condon factors and r-centroid values are evaluated. By correlating the theoretically computed intensities with observed values, the internuclear distance dependence of the electronic transition moments of these two systems is determined for the first time.     

Calculation of the spectroscopic constants for the electronic states A1Σ u+ , B1Πu, C1Πu, D1Σ u+ , and E1Σ u+ of the cesium dimer

The vibrational, rotational, and centrifugal distortion constants have been calculated for the electronic states A ¹Σ _u ⁺ , B ¹Π_u, C ¹Π_u, D ¹Σ _u ⁺ , and E ¹Σ _u ⁺ of the Cs₂ molecule. The calculation was performed on the basis of the semiempirical potential energy curves constructed in this paper. The calculated spectroscopic constants are compared with the experimental data. Original Russian Text ? A.D. Smirnov, 2007, published in Optika i Spektroskopiya, 2007, Vol. 102, No. 1, pp. 23–27.     

K2分子23∏g—13∑u+漫射谱强度的碰撞诱导增强效应

用4415.6?CW激光线获得了5730?附近的K₂分子2³∏_g—1³∑_u⁺漫射荧光谱。实验研究了缓冲气体Ar气压强P对漫射谱峰值强度I_diff的碰撞诱导增强效应。用稳态碰撞模型描述了C¹∏_u—2³∏_g间的能量转移过程,推导出了I_diff-P函数关系,对实验数据进行了令人满意的拟合。这种拟合表明:适当变更实验装置,利用本文模型可以得到C¹∏_u—2³∏_g间的能级交叉速率和碰撞诱导转移速率。 关键词：     

利用双光缔合光谱技术直接测量超冷铯分子0u+(6S1/2+6P1/2)长程态的转动常数的实验研究

实验获得了超冷铯分子6S_1/2+6P_1/2离解限下0_u⁺长程态振动能级v=187的转动常数. 首先利用调制的荧光光谱技术获得了高分辨的转动量子数J=0–6的超冷铯分子纯转动光谱. 利用双光缔合光谱技术, 构建了高精度的频率参考信号, 进而得到了相邻转动能级间的频率间隔. 最后通过非刚性转子模型拟合得到了转动常数和离心畸变常数.     

超冷铯分子0u+(6P3/2)长程态的高灵敏光缔合光谱研究

利用发展的调制俘获损耗荧光光谱技术实验测量了超冷铯分子0_u⁺(6P_3/2)长程态的高灵敏光缔合光谱. 光谱探测范围较国际已有报道扩大了60 cm^-1, 观察到25个长程区域新的振动能级. 通过LeRoy-Bernstein公式对振动束缚能数据进行拟合, 获得了超冷铯分子0_u⁺(6P_3/2)态的长程系数C₃ 为16.103±0.010. 构建了超冷铯分子0_u⁺(6P_3/2)态长程区域的势能曲线.     

Systematic study of the product((E(2_2~+)/E(2_1~+)) * B(E2)↑) through the asymmetric rotor model

A systematic study of the product((E(2_2~+)/E(2_1~+))*B(E2)↑) is carried out in the major shell space Z=50-82,N=82-126 within the framework of the asymmetric rotor model where the asymmetry parameter γ0reflects change in the nuclear structure.A systematic study of the product((E(2+)/E(2+))*B(E2)↑) with neutron number N is also discussed.The product((E(2_2~+)/E(2_1~+))*B(E2)↑) provides a direct correlation with the asymmetry parameter γ0.The effect of subshells is visible in Ba-Gd nuclei with N 82,but not in Hf-Pt nuclei with N 104.We study,for the first time,the dependency of the product((E(2_2~+)/E(2_1~+))*B(E2)↑) on the asymmetry parameterγ0.     

Analysis of the B1Πu → X1Σg+ band system of 7Li2 molecule excited by the 4545- and 5287-Å visible lines of the argon ion laser

Two new fluorescence series have been excited by the two lines at the extreme ends of the range of visible Ar⁺ transitions, 4545 and 5287 Å. In each case the B¹Π_u electronic state of ⁷Li₂ is excited, to levels $\text{v′ = 12, J′ = 13 (4545}\text{A}\text{?}\text{)}$ and $\text{v′ = 2, J′ = 58 (5287}\text{A}\text{?}\text{)}$. Fluorescence to the ground state can be detected in the range 2 ≤ v″ ≤ 23 and 0 ≤ v″ ≤ 8, respectively. Measured relative intensities agree well with calculated radiative transition probabilities reported herein.     

Polarization labelling spectroscopy of the A 1Σ+u band of Na2

A result of the polarization labelling spectroscopy of the A ¹Σ⁺_u band of sodium dimer for the high vibrational quantum number υ'>20 is reported. The frequency difference δv=v_obs-v_cal is found to decrease from 2 to -3 cm^-1 as the rotational levels (υ'=27?30), where v_cal is the calculated transition frequency using the Dunham coefficients of Demtröder and Stock for the X ¹Σ⁺_g band and of Kusch and Hessel for the A ¹Σ⁺_u band.     

A spectroscopic study of the D(0u+) ion-pair state of Br2 by the optical-optical double-resonance technique

An optical-optical double-resonance technique has been applied to study the D(0_u⁺) ion-pair state of Br₂ in a one-photon resonant three-photon absorption. The OODR transition proceeds through the high vibrational level of the B³Π(0_u⁺) state, which compromises a large Franck-Condon shift required for the excitation of Br₂ from the X¹Σ_g⁺ state to the D(0_u⁺) state. Dunham parameters of the D(0_u⁺) state, based on a global least-squares fit of 407 transitions (v′ = 0–16, J′ = 17–115), are Y₀₀ = 49928.443(41), Y₁₀ = 134.467(19), Y₂₀ = ?8.71(27) × 10^?2, Y₃₀ = ?3.36(10) × 10^?3, Y₀₁ = 4.2382(15) × 10^?2, Y₁₁ = ?1.061(36) × 10^?4, Y₂₁ = ?2.00(27) × 10^?6, and Y₀₂ = ?1.93(11) × 10^?8 for ⁷⁹Br₂ (all in cm^?1, and 3σ in parentheses). The single rovibronic fluorescence spectrum of the D(0_u⁺) state shows a transition terminating on the X¹Σ_g⁺ ground state, and establishes the absolute v′ numbering on the basis of the Franck-Condon factor calculations. The v′ = 2 and 3 levels of the D(0_u⁺) state are strongly perturbed due to the heterogeneous interaction with the 1_u state correlating with the same ionic products of the D(0_u⁺) state at the dissociation limit, $\text{Br}{}^{\mathrm{?}}\text{(}{}^1\text{S) +}\text{Br}{}^{\mathrm{+}}\text{(}{}^3\text{P}{}_2\text{)}$.     

Transition densities between the 01+, 21+, 41+, 02+, 22+, 11− and 31− states in 12C derived from the three-alpha resonating-group wave functions

All the multipole transition densities between the seven T = 0 states in ¹²C are calculated with the use of the microscopic 3α resonating-group wave functions which are obtained by dynamically solving the 3α relative motion with the total antisymmetrization taken into account exactly. The observed elastic and inelastic electron scattering form factors for the transition to the 2₁⁺, 4₁⁺, 0₂⁺, 1₁^?and 3₁^? states are well reproduced with no additional effective charge. The existence of a deformed intrinsic state for the 0₁⁺, 2₁⁺and 4₁⁺states is deduced by the analysis of the transition densities between them which are derived by the weak-coupling-type 3α wave functions; the intrinsic density distribution is illustrated. The monopole density distribution of the 0₂⁺, 2₂⁺ and 1₁^?, states is found to be much longer ranged than that of the 0₁⁺, 2₁⁺ and 4₁⁺ states; the 3₁^? state case is intermediate. On the basis of the transition densities between the 0₁⁺, 2₁⁺, 0₂⁺ and 2₂⁺ states, analysis is made of the transition between the shell-like states and the molecule-like states with a large spatial-structure change. Specific, effective nucleon-nucleon interactions are folded into the transition densities here obtained. The evident dependence of the radial shape of the folded nucleon-¹²C form factors on the choice of the interactions and the multi-step form factors for the excitation of the 0₂⁺, 1₁^? and 3₁^? states are discussed.     

Solvatochromic shift of the 0-0 phosphorescence band and change of polarizability in the a 1δg → X 3Σ g? -transition in the oxygen molecule

We used known experimental data to analyze the influence of intermolecular interactions on the position of the 0-0-band a¹Δ_g → X³Σ _g ⁻ phosphorescence of molecular oxygen in solutions. A bathochromic (red) shift caused by dispersion interactions and fluctuations of the internal electric field (induction effect) is analyzed employing new formulas obtained by us in the framework of the Onsager model. The contributions from intermolecular repulsion and higher multipole interactions to the shift of the spectrum are also discussed. It is found that the polarizability in the a¹Δ_g state is higher than in the X³Σ _g ^t- state by 0.19 ± 0.03 ų. Taking into account the induced nature of O₂ phosphorescence in solutions, it is noted that the change of polarizability Δα_eg = 0.19 ų should differ from the change of Δα_eg inherent in free molecular oxygen. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 4, pp. 453–459, July–August, 2007.     

氢分子3pπ D1πu+和4pσ B″1Σu+态的预解离

运用量子亏损理论，并与参考系变换及本征通道R-矩阵法相结合，建立了描述氢分子里德伯态的预解离过程的理论方法．通过对氢分子的3pπD¹π_u⁺和4pσ B″¹Σ_u⁺电子态的预解离过程的研究，阐明其解离的机理，并给出预解离的线宽． 关键词：     

Stereodynamics of the reactions Ne+H2+/Ne+D2+/Ne+T2

The vector correlations between products and reagents for the reactions Ne+H + 2 , Ne+D + 2 , and Ne+T + 2 are calculated by means of the quasi-classical trajectory method on a new potential energy surface constructed by Lü et al. [J. Chem. Phys. 2010 132, 014303]. The polarization-dependent differential cross-sections (2π/σ)(dσ 00 /dω t ), (2π/σ)(dσ 20 /dω t ), (2π/σ)(dσ 22+ /dω t ), and (2π/σ)(dσ 21 /dω t ), and the distributions of P (θ r ), P (φ r ), and P (θ r ,φ r ) are calculated. The isotopic effect, which is associated with the difference in mass factor among the three reactions, is revealed.     

Measurement of the branching ratios for Kμ2+, Kπ2+, Ke3+ and Ke3+ decays using a magnetic spectrometer with streamer chambers

The momenta of ～30 000 charged particles from K⁺ decays were measured using a magnetic spectrometer with streamer chambers. The ratio R = Γ(K_π2⁺)/Γ(K_μ2⁺) = 0.3355 ± 0.0057 was obtained. Our values for the branching ratios are: (63.18±0.43)% for K_μ2⁺, (21.18±0.33)% for K_π2⁺, (3.33±0.51)% for K_μ3⁺, (4.99±0.54)% for K_e3⁺.     

The E → B transition (3000–3140 Å) in Br2

The region 3030–3140 Å of the emission spectrum of Br₂ is reinvestigated using sources containing separated ⁷⁹Br₂ and ⁸¹Br₂. The analysis, which spans v′ levels 0–15 and v″ levels 8–31, indicates that the transition in this region is the analog of the E → B system in I₂, and it is so redesignated. The following spectroscopic constants are obtained for the E state of ⁷⁹Br₂: T_e = 49 779.06 cm^?1, ω_e = 150.46 cm^?1, ω_eχ_e = 0.383 cm^?1, B_e = 0.04172 cm^?1, $\text{R}{}_{\mathrm{e}}\text{= 3.20}\text{A}\text{?}$.