共查询到20条相似文献,搜索用时 46 毫秒
1.
Michael J. Haugh Bruce S. Schneider Allen L. Smith 《Journal of Molecular Spectroscopy》1974,51(1):123-134
Relative emission intensities of sixteen bands of HCl+ (A2Σ+ - X2Πi), four bands of DCl+ (A2Σ+ - X2Πi), and 5 bands of HBr+ (A2Σ - X2Πi) have been made using both ion-beam excitation and microwave discharge sources. Intensities were determined by comparison with computer-generated spectra. Treatment of the data within the r-centroid approximation shows that in HCl+ the electronic transition moment decreases strongly at large [] but levels off at shorter . DCl+ data agree quantitatively with HCl+. The variation in the HBr+ moment is similar, with . 相似文献
2.
Experimental branching ratios for 41 bands of the second positive system of N2 are given. The variation of the electronic transition moment with internuclear separation was studied by using the r-centroid approximation. The result is . 相似文献
3.
The infrared spectrum of yttrium monoiodide has been excited in an electrodeless microwave discharge and explored between 2500 and 12 000cm?1 with a high-resolution Fourier transform spectrometer. A unique system is observed (ν00 = 9905.520 cm?1), which we attribute to a transition and an extensive analysis is made. Rovibrational constants are obtained for both states mainly from a simultaneous multiband fitting. This procedure is applied to the whole set of 2231 observed line wavenumbers in the 1-0, 0-0, and 0–1 bands, yielding a final weighted standard deviation of 0.0038 cm?1. Furthermore, a partial analysis of the 2-0 and 3-1 bands is performed. The following equilibrium constants are derived (cm?1): High-order constants Dv and Hv are also calculated for the various vibrational levels (v′ = 0, 1, 2, 3; v″ = 0, 1). 相似文献
4.
A weak emission spectrum of I2 near 2770 Å is reanalyzed and found to to minate on the A(1u3Π) state. The assigned bands span v″ levels 5–19 and v′ levels 0–8. The new assignment is corroborated by isotope shifts, band profile simulations, and Franck-Condon calculations. The excited state is an ion-pair state, probably the 1g state which tends toward . In combination with other results for the A state, the analysis yields the following spectroscopic constants: T″e = 10 907 cm?1, ″e = 1640 cm?1, ω″e = 95 cm?1, ; T′e = 47 559.1 cm?1, ω′e = 106.60 cm?1, . 相似文献
5.
N.Sreedhara Murthy S.P. Bagare 《Journal of Quantitative Spectroscopy & Radiative Transfer》1980,24(4):319-322
Relative integrated intensities of a few bands in the vibrational structure of the B-X fluorescent system of molecular iodine have been measured by the technique of photographic photometry. Reliable values of Franck-Condon factors and r-centroids given recently by Tellinghuisen have been employed to evaluate the variation of electronic transition moment with internuclear separation. The variation is found to be in the range 2.76 < r < 2.81 Å. Smoothed arrays of band strengths are presented for the bands. The effective vibrational temperature of the source is found to be 340 ± 55 K. 相似文献
6.
Band contour analyses of the absorption bands of 78Se16O2 and 80Se16O2 at 2949 Å, assigned to the 103 transition (King and McLean, in press), show that they are type A, with transition moment directed in-plane and parallel to the line joining the oxygen nuclei. The electronic transition responsible for the B absorption system of the molecule is therefore under the C2v point group. The contour analysis gives the excited state bond angle as 101.0°, and the bond length as 1.74 Å. The latter value is confirmed by Franck-Condon calculations. There is therefore an increase in bond length and a decrease in bond angle upon electronic excitation. This agrees with the predictions of molecular orbital theory. 相似文献
7.
Coulomb effects on cyclotron resonance in two-dimensional electron systems are investigated based on a self-consistent approach which improves the random-phase approximation. The memory function in the dynamic magnetoconductivity depends on the electron density not only through the filling factor v but also on its combination with the dimensionless density parameter rs in the form . The memory function reproduces the data of Wilson, Allen and Tsui for intermediate densities. 相似文献
8.
The electroreflectance of Si under uniaxial stress has been measured in the 3.0–4.0 eV region at 77 K. The results indicate that the dominant structure in this energy region is attributed to Λv3 → Λc1 (or Lv3′ → Lc1 transition. The deformation potentials of these bands are determined to be . 相似文献
9.
The emission spectrum of the He2 molecule has been rephotographed in the ~3200–4100 Å region and the , , and transitions analyzed. The g, k′, and n states, which have not been reported previously, are characterized through v = 1, 2, and 1, respectively. Several small accidental perturbations have been observed in the rotational manifolds of the k′ and n states. 相似文献
10.
Franck-Condon factors and r-centroids of the system of IO molecule have been computed. The dissociation energy of the upper (A) state has been estimated and the dissociation products are determined. 相似文献
11.
The molecular-beam, laser-rf, double-resonance technique has been used to make high-precision measurements of both the v and N dependences of the spin-rotational and hyperfine splittings in the ground state of CaF. The precision (1 ppm) and scope (1 ≤ N″ ≤ 119, 0 ≤ v″ ≤ 4) of the data allow evaluation of many of the parameters (with the Dunham expansion) in the Hamiltonian. The results are compared with new ab initio calculations. 相似文献
12.
13.
The (0,0) band of the emission (Infrared Afterglow) system of molecular nitrogen has been recorded with a resolution of 0.046 cm?1 and a line position accuracy of 0.007 cm?1. Six hundred and seventy-two lines are tabulated into a line list for the 1.53 μm (low-resolution) emission feature. Of these, 482 are assigned as members of the 27 branches of the B′ → B transition, while 150 are identified with the 1PG (3,6) band. Molecular constants for the v = 0 levels of the and B3Πg states have been computed and tabulated. 相似文献
14.
Robert W. Field Richard A. Gottscho E. Miescher 《Journal of Molecular Spectroscopy》1975,58(3):394-413
No perturbation between two valence states of NO has ever been identified, although many valence-Rydberg and several Rydberg-Rydberg perturbations have been extensively studied. The first valence-valence crossing to be experimentally documented for NO is reported here and occurs between the 15N18O B2Π (v = 18) and B′2Δ (v = 1) levels. No level shifts larger than the detection limit of 0.1 cm?1 are observed at the crossings near and ; two crossings involving higher rotational levels could not be examined. Semi-empirical calculations of spin-orbit and Coriolis perturbation matrix elements indicate that although the electronic part of the interaction is large, a small vibrational factor renders the 15N18O B (v = 18) ? B′ (v = 1) perturbation unobservable. Semi-empirical estimates are given for all perturbation matrix elements of the operators and which connect states belonging to the configurations , , and . 相似文献
15.
The vibration-rotation transitions for v = 1 ← 0 of NO () have been studied by using the technique of laser magnetic resonance spectroscopy. Five magnetic resonance lines are observed with three CO laser lines in the range from 1859 to 1886 cm?1. From these, three zero-field transition frequencies, v = 1 ← 0; , , and are obtained with an accuracy of ±0.0007 cm?1. The molecular constants which have been determined by borrowing centrifugal constants from a previous infrared work are , , and . 相似文献
16.
The electronic absorption spectra of thioformaldehyde and thioformaldehyde-d2 have been obtained. A vibrational analysis of the discrete band system in the 6100-4400-Å region is reported. The type A origin bands are at for , and are magnetic dipole allowed. The electronic transition is under the C2v point group. Most of the intensity of the system is in type B bands, and is due to vibronic mixing with higher 1B2 states when the inversion mode ν4 is excited. The molecule in the excited 1A2 state is “floppy-planar,” having a broad potential function with a barrier of the order of 20 cm?1 to the inversion motion. 相似文献
17.
T. Odagaki 《Solid State Communications》1980,33(8):861-865
A probability distribution for the off-diagonal matrix elements vnm of the tight binding Hamiltonian is assumed to be for and P(vnm = 0 otherwise. A homomorphic cluster CPA with the L(E) criterion is used to study localisation in a simple cubic lattice and a computer simulation is used to study a square lattice with the participation-ratio criterion. It is found, in both cases, that Anderson's transition takes place for a critical degree of disorder. 相似文献
18.
Richard E. Smalley Lennard Wharton Donald H. Levy Dean W. Chandler 《Journal of Molecular Spectroscopy》1977,66(3):375-388
The fluorescence excitation spectrum of the transition in s-tetrazine has been observed and measured. The sample was cooled to a rotational temperature of <1 K by expansion in a supersonic free jet. In this way the rotational structure arising from asymmetry split low J lines could be observed. The rotational A and B axes of the 2H112C214N4 isotope were observed to interchange upon electronic excitation and a theory describing the effect of this interchange upon the optical selection rules has been developed. Analysis of the resolved rotational structure suggests that the geometry change upon electronic excitation is smaller than that deduced from previous analysis of the room temperature optical spectrum. 相似文献
19.
E.V. Doktorov I.A. Malkin V.I. Manko 《Journal of Quantitative Spectroscopy & Radiative Transfer》1976,16(12):1021-1029
By means of the factorization method, recurrence relations for the matrix elementS for an arbitrary positive integer N are obtained in the framework of α-averaging for the Morse potential. The method of calculating the matrix element is outlined, provided a dependence of the electronic transition moment Re on the internuclear distance r can be approximated by the polynomial Re(r)=a0+a1r+a2r2+…+ainNrN. Recurrence relations are also obtained for the case of the exponential dependence Re(r). 相似文献
20.
Rolf Engleman 《Journal of Molecular Spectroscopy》1974,49(1):106-116
The low J rotational lines of the (v′=v″; v″=0, 1, …, 7) and (v′=v″+1; v″=0, 1, …, 6) bands of the B2Σ+ → X2Σ+ transition in the CN free radical have been measured from absorption spectra obtained during the flash photolysis of low pressure BrCN in excess argon. Rotational analysis has yielded accurate molecular constants for these states. A perturbation between the B2Σ+ (v′ = 5) and (v′ = 17) states has been found and analyzed. 相似文献