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1.
Using Doppler-free polarization spectroscopy, the hyperfine structure of the B-X system of 79Br2 was measured for the levels B3Π0+u, v′ = 16–28, and X1Σg+, v″ = 1, 2. Besides the nuclear electric quadrupole coupling, the magnetic spin-rotation interaction was analyzed, which varies strongly with the vibrational energy of the electronically excited state. This behavior originates from a perturbing repulsive state Ω = 1u, the potential of which can be estimated in this way. 相似文献
2.
Arrays of Franck-Condon factors q(v′, v″) and r-centroids r(v′, v″) were computed using Morse potentials for C1Π [sbnd] X1Σ+ g and B O+ u [sbnd] X1Σ+ g bands of the 107Ag 109Ag molecule. 相似文献
3.
《Journal of Molecular Spectroscopy》1987,125(1):1-13
The intensities of the laser-induced fluorescence spectra of 130Te2, excited by Ar+ and He-Cd+ lasers, are measured for the AOu+-XOg+ and BOu+-XOg+ systems. The RKR potentials of the A, B and X states are calculated. These potentials are used for calculating Franck-Condon factors and r-centroids with due respect to rotation. The relative r-centroid dependences of the electronic transition strength were obtained first and then normalized in lifetimes. 相似文献
4.
Examination of two new low-lying electronic states of SiS observed in chemiluminescent flame spectra
C. Linton 《Journal of Molecular Spectroscopy》1980,80(2)
Diatomic silicon sulfide molecules have been produced in the chemiluminescent reaction of silicon atoms with OCS. Spectra of the resulting flame consist mainly of two new band systems in the region 350–400 and 385–600 nm. These systems have been assigned as b 3Πr-X 1Σ+ and a 3Σ+-X 1Σ+ on the basis of band structure, spin-orbit splitting, molecular constants, and comparison with chemiluminescent spectra of isovalent molecules. Vibrational assignments were made with the help of the isotope effect and vibrational constants were obtained. Rotational structure was observed in some a-X bands and a partial analysis yielded an approximate rotational constant, B 0.247 ± 0.007 cm−1, for the a 3Σ+ state. Franck-Condon factors, calculated for the a-X system, are shown to fit the general trend of the intensity distribution. Irregularities in spin-orbit splitting and in relative intensities of the spin-orbit components of the b 3Π-X 1Σ+ system were observed and an attempt is made to explain them in terms of interactions with neighboring states. Addition of active nitrogen to the flame was shown to greatly increase the intensity of the b-X system relative to the a-X system. Constants (in cm−1) obtained for the new state are: a3σ+: Te=24 582.1 ± 1.3, ωe=503.8±1.0, ωexe=1.86±0.21b3σ+: Te=27 314.5 ± 2.2, ωe=619.4±2.0, ωexe=5.75±0.52b3σ+: Te=27 407.9 ± 1.1, ωe=524.3±1.2, ωexe=3.97±0.28 相似文献
5.
《Journal of Molecular Spectroscopy》1986,116(1):43-47
The emission spectrum of the B3Πg-A3Σu+ system of the 15N2 molecule was recorded between 3500 and 12 500 cm−1 with a high-resolution Fourier spectrometer. Twelve bands with 0 < v′ < 5 and 0 < v″ < 9 are analyzed. The molecular parameters of the B3Πg and A3Σu+ states are obtained by a complete fitting procedure. Derived values of equilibrium constants are deduced; the Franck-Condon factors are calculated for the B-A system of 15N2. 相似文献
6.
J. A. Coxon 《Journal of Molecular Spectroscopy》1974,50(1-3)
24 bands of the B3Π(0+) ← X1Σ+ system of 79Br35Cl and 81Br35Cl have been photographed at high resolution. Direct least-mean square fits of the measured line frequencies were made to determine band origins and rotational constants in the ranges 1 ≤ v″ ≤ 7, 2 ≤ v′ ≤ 8. A reiterative procedure was adopted in which the higher order centrifugal distortion constants (Dv, Hv) were constrained to theoretical values calculated from RKR potential curves. The results of the analysis are used to obtain a set of Franck-Condon factors and r-centroids for the B-X system of BrCl. 相似文献
7.
The observation of the c3Πu-X1Σg+ intersystem transition of P2 is reported. The 6-0 band of the system was identified on high resolution absorption plates teken on the NRC 10-m vacuum spectrograph at Ottawa. A rotational analysis of the band is given together with that of the adjacent 5-0 band of the C1Σu+-X1Σg+ system, the upper level of which is involved in a mutual perturbation with the c3Πu, v = 6 level. The interaction parameters for the perturbation are derived. It is proposed that the appearance of the 6-0 band of the c3Πu-X1Σg+ transition is due to intensity borrowing from the strong, allowed C1Σu+-X1Σg+ system. Accurate values for the energies of the c3Πu, b3Πg, and a3Σu+ states relative to the ground state are given. The analysis of two other bands, 2-0 and 7-0, of the C1Σu+-X1Σg+ system whose upper levels likewise interact strongly with the c3Πu state are also given. 相似文献
8.
A. D. Smirnov 《Optics and Spectroscopy》2010,109(5):680-686
Vibrational, rotational, and centrifugal spectroscopic constants and radiative parameters, i.e., the Einstein coefficients,
oscillator strengths, and wave numbers for vibrational transitions in electronic systems of bands A
1Σ
u
+-X
1Σ
g
+ (0 ≤ v′ ≤ 25; 0 ≤ v″ ≤ 44), B
1Π
u
-X
1Σ
g
+ (0 ≤ v′ ≤ 29; 0 ≤ v″ ≤ 47), and the radiative lifetimes for the vibrational levels of excited states of the sodium dimer,
are calculated. The calculations are carried out based on semiempirical potential curves constructed in this study. The calculated
spectroscopic constants and radiative lifetimes are compared to the experimental values. 相似文献
9.
A reinvestigation of the A0+-X10+ band system, the most electronic transitions reported for bismuth monofluoride, is presented. Approximately 65 bands were photographed in emission between 4220 and 5417 Å, of which 33 were rotationally analyzed. Inconsistencies in earlier vibrational analyses were resolved. Rotational constants for 0 ≤ ν′ ≤ 12 and 0 ≤ ν″ ≤ 18 were determined from direct least-squares fitting to the measured line positions of each band. “Merging” of the overdetermined constants was performed to obtain the best single estimate of each parameter. The resulting minimum-variance linear unbiased estimates were used to calculate RKR potential curves. Franck-Condon factors and r centroids were subsequently obtained and are presented. Evidence is given for predissociation in the upper state; perturbations involving levels above the crossing point are correlated with those previously reported in the B0+ state. The upper limit of the ground-state dissociation energy (3.14 eV) is in accord with extrapolated values as given in earlier investigations. The nature of a postulated third interacting state is also discussed. 相似文献
10.
Na2 excited from the X1Σg+ state to the A1Σu+ state by a narrow band (3 MHz) Rhodamine-6G dye laser at 6022.3 Å, the same wavelength at which Na undergoes the 3s–5s two-photon transition, gives four fluorescence series from A1Σu+ levels (v′ = 21, J′ = 26), (18, 33), (33, 19), and (34, 50). The last two series are much weaker in intensity, and at long wavelengths many doublets are lost in the background noise. The same (34, 50) fluorescence series was found by other workers in the lab using a Kr+ (5682 Å) laser as excitation source. Their analysis agrees very well with the findings in the work. 相似文献
11.
P. Saraswathy K. Sunanda 《Journal of Quantitative Spectroscopy & Radiative Transfer》2008,109(7):1252-1259
The B0u+-X0g+ and B1u-X1g transitions of 80Se2 and 78Se2 are reinvestigated. Several new bands are reported, especially for the B1u-X1g 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. 相似文献
12.
Pawel Kowalczyk Shunji Kasahara Md.Humayun Kabir Hajime Kat 《Journal of Molecular Spectroscopy》2003,220(2):162-169
The E(4) 1Πu←X 1Σ+g band system of the K2 molecule is investigated by the technique of Doppler-free optical–optical double resonance polarization spectroscopy. The observed vibrational levels v=0 to 9 of the E state are subject to numerous rotational perturbations by the neighboring 4 3Πu, 4 1Σ+u, and 5 3Σ+u electronic states. By using deperturbation methods, the potential curves of the 4 1Πu and 4 3Πu states are determined as well as some properties of the 4 1Σ+u and 5 3Σ+u state potentials. The results are compared with predictions of ab initio calculations. 相似文献
13.
The decay pathways of the structured ionization region of oxygen at different momentum transfers,i.e.,0,0.23 a.u.(atomic unit),and 0.91 a.u.,are studied by measuring the ion and the scattered electron coincidently.It is found that the dipole-forbidden superexcited states of(2σu)-1(c4Σu-)npσu 3Σg-← X3Σg-decay into different channels according to the principal quantum number n.The broad ridge above 35 eV,which may be due to inner-valence excited states of(2σg)-1nλ or multiply excited states,is observed both at small and large momentum transfers,and its decay channel of O++ O is dominant. 相似文献
14.
A. Pashov P. Popov H. Knöckel E. Tiemann 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,46(2):241-249
We report on high resolution Fourier-transform spectroscopy of fluorescence to the a3Σu
+ state induced by two-photon or two-step excitation from the X1Σg
+ state to the 23Πg state in the molecule K2. These spectroscopic data are combined with recent results of Feshbach resonances and two-color photoassociation spectra
for deriving the potential curves of X1Σg
+ and a3Σu
+ up to the asymptote. The precise relative position of the triplet levels with respect to the singlet levels was achieved
by including the excitation energies from the X1Σg
+ state to the 23Πg state and the frequencies of the fluorescence down to the a3Σu
+ state in the simultaneous fit of both potentials. The derived precise potential curves allow for reliable modeling of cold
collisions of pairs of potassium atoms in their 2S ground state.
Electronic supplementary material Supplementary Online Material 相似文献
15.
In this paper, the question of reliability of the Morse potential as a potential curve for a diatomic molecule is investigated on the basis of calculating the rotational constant. It is shown that the Morse potential describes well potential curves of X1Σ q + and B1Πu electronic states of a Na2 molecule. Calculations of Franck-Condon factors for X1Σ q + ? B1Πu band of a Na2 molecule using wave functions of the Morse potential confirm the known correlation between the values of Franck-Condon factors and rotational constants of combined electronic states. 相似文献
16.
Whang T. J. Tsai C. C. Stwalley W. C. Lyyra A. M. Li L. 《Journal of Molecular Spectroscopy》1993,160(2)
The Na2(3sσg)(4sσg) 23Σ+g state of Na2 has been observed and studied by cw perturbation-facilitated optical-optical double-resonance (PFOODR) spectroscopy for the first time. A single-mode dye laser and a Ti-sapphire laser served as the pump and the probe lasers, respectively. A total of 543 PFOODR excitation signals have been assigned to the 23Σ+g ← b3Π1u transitions. Absolute vibrational numbering was determined by counting nodes in the 23Σ+g → a3Σ+u bound-free spectra. Spectroscopic constants and the corresponding RKR potential energy curve are presented in this vsork. The values of Te, Re, and De, are found to be 25 551.237(49) cm−1, 3.53463(35) Å, and 6211.5(1) cm−1 respectively. 相似文献
17.
Yan Chen Lunhua Deng Xuping Shao Jingxia Chen Yangqin Chen Xiaohua Yang 《Journal of Quantitative Spectroscopy & Radiative Transfer》2009,110(18):2208-2211
High resolution absorption spectra of the (4, 20) band in the second negative system (A2Πu–X2Πg) of O2+ cation were measured and analyzed in the range of 11 900–12 300 cm–1 via optical heterodyne velocity modulation spectroscopy. Precise molecular constants of the levels involved were obtained by a nonlinear least-squares fitting procedure combining with our previous spectra of the (4, 19) and (6, 20) bands. 相似文献
18.
Wei-Tzou Luh Vassilis Zafiropulos Paul D. Kleiber William C. Stwalley Shawn P. Heneghan 《Journal of Molecular Spectroscopy》1985,111(2):327-343
The gold vapor laser has been used to irradiate the alkali dimers Li2, Na2, K2, and Rb2. Significant fluorescence was found only from Na2 and K2. Six fluorescent series in the A1Σu+-X1Σg+ system of Na2 and three in the B1Πu-X1Σg+ system of K2 were assigned, respectively. New spectroscopic constants for the X1Σg+ state of 39K2 are derived, and new RKR potential energy curves for the X1Σg+ and B1Πu states of 39K2 are given. 相似文献
19.
The relative intensities of vibrational bands corresponding to the photoionization reactionX1Σg+(υ″ = 0) + hv → X2Σg+(υ′ = 0, 1, 2 …) + e? have been measured for H2, HD and D2, using He I radiation and a cylindrical mirror analyzer. These relative intensities differ significantly from squared overlap integrals (Franck-Condon factors) based on accurate potential curves for X1Σg+ and X2Σg+, but are in good agreement with calculations performed by Itikawa which include the variation of transition moment with internuclear distance and the kinetic energy of the departing electron. 相似文献
20.
The B3Πg-A3Σu+ system of N2 excited in a microwave discharge was recorded between 3 000 and 18 000 cm?1 with a high-resolution Fourier spectrometer. There are no observed irregularities in the levels of the A3Σu+ and B3Πg states at least for the values of v and J considered here, except the predissociation in the B3Πg state for v = 12 and J higher than 33. This predissociation will be checked with more complete data in another article. Thirty three bands of the first positive system with 0 ≤ v′ ≤ 12 and 0 ≤ v″ ≤ 8 are analyzed. The molecular parameters of the B3Πg and A3Σu+ are obtained by a complete fitting procedure. Derived values of equilibrium constants are deduced; RKR potential energy curves for the two states are constructed, and the Franck-Condon factors calculated for the A-B system. 相似文献