High-Resolution Study of the First Hexad of D(2)O

The high-resolution Fourier transform spectra of the D(2)O molecule have been recorded and assigned in the 4200-5700 cm(-1) region where the vibration-rotation bands 2nu(1), 2nu(3), nu(1) + nu(3), nu(1) + 2nu(2), 2nu(2) + nu(3), and 4nu(2) are located. The presence of numerous and very strong accidental perturbations between the states of the hexad makes it necessary to take into account not only ordinary resonance interactions of the Fermi, Darling-Dennison, and/or Coriolis types, but interactions between the states (v(1)v(2)v(3)) and (v(1) -/+ 2v(2) +/- 2v(3) +/- 1) as well. Parameters of all six vibrational states of the hexad were obtained from the fit of experimental energy values. Copyright 2000 Academic Press.     

Rotational Analysis of the Ground State and the Lowest Fundamentals nu(3), nu(5), and nu(6) of (13)CH(3)D

The nu(3), nu(5), and nu(6) fundamental bands of the (13)CH(3)D molecule have been studied with Fourier transform infrared spectroscopy. The spectra and results for the parent species (12)CH(3)D (O. N. Ulenikov, G. A. Onopenko, N. E. Tyabaeva, J. Schroderus, and S. Alanko, J. Mol. Spectrosc. 193, 249-259 (1999)) have been used to assign and analyze about 1900 lines belonging to the (13)CH(3)D isotopic species. About 850 ground state combination differences with DeltaK = 0 were calculated, which allowed us to determine the J-dependent ground state rotational constants. The K-dependent constants as well as those describing the a(1)-a(2) (K = 3) splitting were fixed to the values obtained for the (12)CH(3)D species. The (v(3) = 1), (v(5) = 1), and (v(6) = 1) states were fit simultaneously by including the intervibrational interactions in the Hamiltonian. The rotational energies, the rotational and centrifugal distortion constants, as well as the resonance parameters involving the three states have been determined and discussed. Copyright 2000 Academic Press.     

The Rotational Spectra, Isotopically Independent Parameters, and Interatomic Potentials for the X(1)(2)Pi(3/2) and X(2)(2)Pi(1/2) States of BrO

Observations of the rotational spectrum of BrO have been extended to include vibrational levels up to v = 8 in the X(1)(2)Pi(3/2) and v = 7 in the X(2)(2)Pi(1/2) states. The rotational spectra of isotopically enriched Br(18)O, X(1), v = 0, 1 and X(2), v = 0 have been observed as well. The spectra of all four isotopic species have been fit to a Hamiltonian in which the parameters have fixed isotopic ratios. An extensive set of isotopically independent parameters has been determined. Interatomic potentials have been derived for both the X(1) and X(2) states. The hyperfine constants and their vibrational dependencies have been determined more precisely and several of them have been determined for the first time. These are interpreted in terms of the electronic structure of the molecule. The isotope relations among the constants have provided a means of decorrelating the electron spin-rotation constant gamma from the fine-structure centrifugal distortion constant, A(D), and have allowed the first determination of an effective value for gamma. Copyright 2001 Academic Press.     

CO三重带系d3Δ-a3Π(4,0)和(5,0)带激光光谱研究

光外差磁旋转浓度调制激光光谱技术属于一种高灵敏度的吸收光谱测量方法 ,可以用于瞬态分子和激发态分子光谱的检测。采用这种技术分别在 16 4 0 0～ 16 6 5 0cm-1和 174 5 0～ 1775 0cm-1波段内直接观测到CO三重带系d3 Δ←a3 Π(4,0 ) (5 ,0 )振转吸收光谱。这种跃迁的上态d3 Δ1(v =4 ) ,d3 Δ2 (v =4 ) ,d3 Δ1(v =5 )分别与A1Π(v =0 ) ,D1Δ(v =0 )和A1Π(v =1)态存在微扰相互作用。通过对所测量到的 CO三重带系 (4,0 ) (5 ,0 )振转谱带作了包含微扰相互作用在内的分析 ,获得了上态d3 Δ(v =4 ,5 )的精确的分子转动光谱常数。     

High-Resolution Infrared and Millimeter-Wave Study of the Fermi-Coupled v(2) = 1 and v(3) = 2 States of DSiF(3)

The nu(2) (nu(eff.) 854.841 cm(-1)) and 2nu(3) infrared bands (nu(eff.) 840.083 cm(-1)) of DSiF(3) have been studied with a resolution of 2.5 x 10(-3) cm(-1). Moreover, millimeter-wave transitions in the v(2) = 1 and v(3) = 2 states up to J" = 33 have been measured. The assignments and fit of the poorly resolved, compressed cluster-type 2nu(3) IR transitions have been confirmed by a simultaneous study of the 2nu(3)-nu(3) band. The constant W = 5.116 cm(-1) of the Fermi interaction between the v(2) = 1 and v(3) = 2 levels has been determined from frequency effects which are in agreement with relative intensities of the nu(2) and 2nu(3) bands. The deperturbed (B(0) - B(v)) and (C(0) - C(v)) values of the states involved agree with their ab initio predictions within 7% in the worst case. Copyright 2001 Academic Press.     

Laser-Excited Fluorescence Spectra of Strontium Monoiodide

Fluorescence spectra of strontium monoiodide excited by Ar++ and Kr+ laser lines have been analyzed by Fourier transform spectrometry. Rotational levels have been populated either directly or after collisional relaxation: (i) in D2Sigma+ (v = 0, 1) by ultraviolet lines of Ar++, inducing numerous fluorescence transitions ending in the levels v = 0-3 of the strongly interacting A2Pi and B2Sigma+ states, (ii) in A2Pi3/2 (v = 0-4) by Kr+ line at 676.44 nm, de-exciting into transitions to X2Sigma+ (v = 0-6). Deperturbed constants for A2Pi and B2Sigma+ states and A approximately B interaction parameter are calculated from the numerical treatment of D2Sigma+ (v = 0, 1) --> A2Pi (v = 0-3) approximately B2Sigma+ (v = 0-3) transitions. Rotational constants for D2Sigma+ (v = 0, 1) are obtained for the first time. The wavenumbers of some 670 fluorescence lines are cataloged. Copyright 1999 Academic Press.     

Molecular photodetachment microscopy

The photodetachment microscopy technique, which was originally used with atomic negative ions, is now applied to a molecular anion. The interferograms of several rotational thresholds corresponding to transitions from OH- X (1)Sigma(+) v=0 states to OH X (2)Pi(3/2,1/2) v=0 states have been recorded. No effect due to the 1/r(2) dipolar potential of the neutral molecule appears. Using a double-pass scheme of the laser on the negative ion beam, we measure the energy of the first few detachment thresholds with improved accuracy. The new recommended value of the electron affinity of 16OH is 14,740.996(13) cm(-1), or 1.827 650 3(17) eV.     

考虑自旋-轨道耦合效应下SeH^-阴离子的光谱和跃迁性质

采用高精度的从头算方法研究了SeH阴离子的基态(X1∑+)和低激发(a3Π,A1Π,b3∑+,21∑+)的势能曲线、偶极矩和跃迁偶极矩.在计算中考虑了价-芯(CV)电子关联、Davidson修正、标量相对论修正和自旋-轨道耦合效应(SOC).考虑了SOC效应后,b3∑0-+和b3∑1+态变为了弱束缚态.计算得到a3Π1X1∑0++,a3Π0+■X1∑0++和A1Π1■X1∑0++跃迁具有很大的跃迁偶极矩.这三种跃迁都同时具有高对角分布的弗兰克-康登因子f00及振动分支比R00.计算得到了a3Π1,a3Π0和A1Π1激发态的自发辐射寿命都很短,能够实现对SeH-阴离子的快速激光冷却.A1Π1■X1∑0-+跃迁为三能级跃迁,中间态的存在对构建准闭合的循环能级的影响可以忽略.驱动a3Π1■X1∑0++,a3Π0+■X1∑0++和A1Π1■X1∑0++跃迁进行激光冷却SeH-阴离子的激光波长都在可见光范围内.本文的结果为以后激光冷却SeH-阴离子的实验提供了部分理论参考.     

Torsional Splitting in the Degenerate Vibrational States of (70)Ge(2)H(6): Rotation-Torsion Analysis of the nu(7) and nu(9) Fundamentals

The rotational and torsional structure of the nu(7) and nu(9) degenerate fundamentals of (70)Ge(2)H(6) has been analyzed under high resolution. The torsional structure of both v(7) = 1 and v(9) = 1 states can be fitted by a simple one-parameter formula. The x,y-Coriolis interaction with the parallel nu(5) fundamental was accounted for in the analysis of nu(7). A strong perturbation of the J structure of the E(3s) torsional component of the KDeltaK = -2 subbranches of nu(9) can be explained by the resonance with an E(3s) excited level of the pure torsional manifold. The perturber is centered at 361.58 cm(-1), very close to the value estimated with a barrier height of 285 cm(-1). This confirms that the fundamental torsional wavenumber is close to 103 cm(-1), in good agreement with the "ab initio" prediction. The torsional splittings of all the infrared active degenerate fundamentals, nu(7), nu(8), and nu(9), follow the trend predicted by theory, and have been fitted by exploratory calculations accounting only for the torsional Coriolis-coupling mechanism of all degenerate vibrational fundamentals in several torsional states. This confirms that torsional Coriolis coupling is the dominant mechanism responsible for the decrease of the torsional splitting in the degenerate vibrational states. A higher value of the barrier had to be used for the nu(9) mode. Copyright 2000 Academic Press.     

Ni2+:RbMgF3的电子顺磁共振谱的研究

含有过渡金属离子的晶体的光学吸收谱、零场分裂D值和g因子与晶体结构有密切关系,应用Ni^2 的参量化d轨道和三角晶场中d^8电子组态的强场能量矩阵,通过建立完全对角化方法,精确地计算了具有C3ν和D3d两种对称的Ni^2 ：RbMgF3的电子顺磁共振谱,分析了Ni^2 ：RbMgF3的零场分裂D值和g因子与晶体结构参量R和θ的依赖关系。理论值与实验值符合得很好。     

Observation of new states decaying into Lambda(c)(+)Kappa(-)pi(+) and Lambda(c)(+)Kappa(0)/(s)pi(-)

We report the first observation of two charmed strange baryons that decay into Lambda(c)(+)Kappa(-)pi(+). The broader of the two states is measured to have a mass of 2978.5+/-2.1+/-2.0 MeV/c2 and a width of 43.5+/-7.5+/-7.0 MeV/c2. The mass and width of the narrow state are measured to be 3076.7+/-0.9+/-0.5 MeV/c;{2} and 6.2+/-1.2+/-0.8 MeV/c2, respectively. We also perform a search for the isospin partner states that decay into Lambda(c)(+)Kappa(0)/(s)pi(-) and observe a significant signal at the mass of 3082.8+/-1.8+/-1.5 MeV/c2. The data used for this analysis were accumulated at or near the Upsilon(4S) resonance, using the Belle detector at the e+ e- asymmetric-energy collider KEKB. The integrated luminosity of the data sample used is 461.5 fb(-1).     

The nu(1) and nu(3) Bands of the (17)O(16)O(17)O Isotopomer of Ozone

Using 0.002 cm(-1) resolution Fourier transform absorption spectra of an (17)O-enriched ozone sample, an extensive analysis of the nu(3) band together with a partial identification of the nu(1) band of the (17)O(16)O(17)O isotopomer of ozone has been performed for the first time. As for other C(2v)-type ozone isotopomers [J.-M. Flaud and R. Bacis, Spectrochim. Acta, Part A 54, 3-16 (1998)], the (001) rotational levels are involved in a Coriolis-type resonance with the levels of the (100) vibrational state. The experimental rotational levels of the (001) and (100) vibrational states have been satisfactorily reproduced using a Hamiltonian matrix which takes into account the observed rovibrational resonances. In this way precise vibrational energies and rotational and coupling constants were deduced and the following band centers nu(0)(nu(3)) = 1030.0946 cm(-1) and nu(0)(nu(1)) = 1086.7490 cm(-1) were obtained for the nu(3) and nu(1) bands, respectively. Copyright 2000 Academic Press.     

Intensity Measurements and Collision-Broadening Coefficients for the Oxygen A Band Measured by Intracavity Laser Absorption Spectroscopy

High-sensitivity, high-resolution intracavity laser absorption spectroscopy (ICLAS) has been used to measure line intensities, nitrogen-broadening coefficients, and self-broadening coefficients in the A band (b(1)Sigma(+)(g) <-- X(3)Sigma(-)(g)) of oxygen. Both linear cavity and ring cavity ICLAS configurations were used for these measurements, and the results were intercompared. The results were compared to values measured using long-path multiple-reflection cells by K. D. Ritter and T. D. Wilkinson [J. Mol. Spectrosc. 121, 1-19 (1987)] and L. Brown and C. Plymate, [J. Mol. Spectrosc. 199, 166-179 (2000)]. New results are included for weakly absorbing transitions, not observed in the earlier measurements, such as high rotational states (up to J = 39), hot-band transitions (v' = 1 <-- v" = 1), and isotopically substituted species ((18)O(2) and (16)O(18)O). Isotopic variants ((16)O(2), (18)O(2), and (16)O(18)O) have similar broadening coefficients for corresponding rotational levels, but the self-broadening coefficients are larger in the hot band (v' = v" = 1) as compared with v' = v" = 0 transitions. An ECS-EP scaling analysis of the v' = v" = 0 self-broadening data accurately represents the available data, with the exception of the N = 0 and N = 1 levels. Copyright 2000 Academic Press.     

The v(1)+v(3) Bands of the (16)O(17)O(16)O and (16)O(16)O(17)O Isotopomers of Ozone

Using 0.002 cm(-1) resolution Fourier transform absorption spectra of an (17)O enriched ozone sample, an extensive analysis of the v(1)+v(3) bands of the (16)O(17)O(16)O and (16)O(16)O(17)O isotopomers of ozone has been performed for the first time. The experimental rotational levels of the (101) vibrational states were satisfactorily reproduced using a Hamiltonian matrix that takes into account the observed rovibrational resonances. More precisely, for (16)O(17)O(16)O, as for the other C(2v)-type ozone isotopomers, it was necessary to account for the Coriolis type resonances linking the (101) rotational levels with the levels of the (200) and (002) vibrational states and the Darling-Dennison interaction coupling the levels of (200) with those of (002). For the C(s)-type isotopomer, namely (16)O(16)O(17)O, as for (16)O(16)O(18)O and (16)O(18)O(18)O, it proved necessary to also account for an additional DeltaK(a)&equals+/-2 resonance involving the rotational levels from (101) and (002) (J.-M. Flaud and R. Bacis, Spectrochimica Acta Part A 54, 3-16 (1998)). Using a Hamiltonian matrix which takes these resonances explicitly into account, precise vibrational energies and rotational and coupling constants were deduced, leading to the following band centers: v(0)(v(1)+v(3))=2078.3496 cm(-1) for (16)O(17)O(16)O and v(0)(v(1)+v(3))=2098.8631 cm(-1) for (16)O(16)O(17)O. Copyright 2001 Academic Press.     

High Resolution FTIR Spectroscopy of DCCCl: Anharmonic Resonances in the nu(1) and nu(2) Bands

High-resolution infrared spectra of the nu(1) and nu(2) bands of DCCCl were observed using Bruker IFS 120HR Fourier transform spectrometers at resolutions of 0.0044 and 0.0035 cm(-1), respectively. For the DCC(35)Cl isotopomer, the nu(1) as well as the nu(2) band was found to be heavily perturbed. Detailed analyses revealed that the nu(1) state is in resonance with the l=0 substate of the nu(3)+4nu(4) state and that the nu(2) state is in resonance with the l=0 substate of the nu(3)+4nu(5) state. The rotational constants played a key role in identifying the perturbing states. In contrast, for the DCC(37)Cl isotopomer, the rotational structures of the nu(1) and nu(2) states are almost regular but slightly perturbed by interactions with the nu(3)+4nu(4) and nu(3)+4nu(5) states, respectively. The constants of resonances as well as the molecular constants for the nu(1), nu(2), nu(3)+4nu(4) and nu(3)+4nu(5) states were determined. Copyright 2001 Academic Press.     

Extended Analysis of Line Positions and Intensities of Ozone Bands in the 2900-3400 cm Region

The 2900-3400 cm⁻¹ spectral range is revisited for an accurate determination of line positions and line intensities of the 3ν₃, ν₁+2ν₃, 2ν₁+ν₃, and 3ν₁ bands of ozone. The fit on 4520 rotational energy levels of (012), (111), (210), (130), (003), (102), (201), and (300) vibrational states determined from observed transitions of cold and hot bands in the 2400-3400 cm⁻¹ region with J_max=65 and K_{a max}=20 gives a r.m.s.=7×10⁻⁴ cm⁻¹ and provides a satisfactory agreement between calculated and observed line positions (dimensionless standard deviation is χ=1.44). The set of 2580 line intensities of 7 rovibrational bands has been measured and fitted with a r.m.s.=6.9% (χ=1.2), leading to the determination of transition moment parameters for these bands. Using these parameters we have obtained more precise estimation for the integrated band intensities S(3ν₃)=1.41×10⁻¹⁹, S(ν₁+2ν₃)=1.28×10⁻²⁰, S(2ν₁+ν₃)=7.91×10⁻²¹, S(3ν₁)=4.72×10⁻²² cm⁻¹/mol cm⁻² at 296 K, with a cutoff 2×10⁻²⁶ cm⁻¹/mol cm⁻². The interactions of the tetrad (003)/(102)/(201)/(300) with the (130) state and the tetrad (040)/(012)/(111)/(210) are studied.     

High resolution study of near-infrared emission spectra of NdO

High resolution near-infrared emission spectra of ¹⁴²NdO have been recorded using a Fourier transform spectrometer. Molecules were produced by heating ¹⁴²Nd₂O₃ to about 2100 K in a special furnace in presence of argon gas. Some 44 bands appear in the region between 7500 and 12 600 cm⁻¹, 19 of which classified into 11 systems involving 11 Ω states have been analyzed in rotation. Three of these systems were known from previous studies at moderate resolution which settled the symmetry Ω=4 of the ground state [L.A. Kaledin, E.A. Shenyavskaya, I. Kovacs, Acta Phys. Hung. 54 (1983) 189]. From the present analysis, information is obtained for the ground state in the levels v=0,1,2, and for the low-lying (1)5, (1)3, and (2)4 states in the levels v=0,v=0,1, and v=0, respectively; the (1)5 and (1)3 states show measurable Λ-doubling. The seven upper states either are perturbed or present anomalous Λ-doubling in the levels investigated; for three of them the perturbations could be reduced using a simple 2 × 2 interaction model. Their Ω symmetry could be ascribed (two states with Ω=3, four states with Ω=4, and one state with Ω=5).     

Optical-Optical Double Resonance Spectroscopy of the H1(u)((3)P(1))-A(3)Pi(1u)-X(1)Sigma(+)(g) Transition of I(2)

We report the analysis of the H1(u)((3)P(1)) state of I(2) by optical-optical double resonance. This state lies in the second tier of ion-pair states and its observation was achieved by using the (1 + 2) photoexcitation sequence using the A(3)Pi(1u) state as an intermediate. The molecular parameters were obtained from data for 0 相似文献   

Fourier Transform Emission Spectroscopy of the Low-Lying Electronic States of NbN

The high-resolution spectrum of NbN has been investigated in emission in the 3000-15 000 cm(-1) region using a Fourier transform spectrometer. The bands were excited in a microwave discharge through a mixture of NbCl(5) vapor, approximately 5 mTorr of N(2), and 3 Torr of He. Numerous bands observed in the near-infrared region have been classified into the following transitions: f(1)Phi-c(1)Gamma, e(1)Pi-a(1)Delta, C(3)Pi(0+)-A(3)Sigma(-)(1), C(3)Pi(0-)-A(3)Sigma(-)(1), C(3)Pi(1)-a(1)Delta, C(3)Pi(1)-A(3)Sigma(-)(0), d(1)Sigma(+)-A(3)Sigma(-)(0), and d(1)Sigma(+)-b(1)Sigma(+). These observations are consistent with the energy level diagram provided by laser excitation and emission spectroscopy [Y. Azuma, G. Huang, M. P. J. Lyne, A. J. Merer, and V. I. Srdanov, J. Chem. Phys. 100, 4138-4155 (1993)]. The missing d(1)Sigma(+) state has been observed for the first time and its spectroscopic parameters are consistent with the theoretical predictions of S. R. Langhoff and W. Bauschlicher, Jr. [J. Mol. Spectrosc. 143, 169-179 (1990)]. Rotational analysis of a number of bands has been obtained and improved spectroscopic parameters have been extracted for the low-lying electronic states. The observation of several vibrational bands with v = 1 has enabled us to determine the vibrational intervals and equilibrium bond lengths for the A(3)Sigma(-)(0), a(1)Delta, b(1)Sigma(+), d(1)Sigma(+), and C(3)Pi(1) states. Copyright 2000 Academic Press.