共查询到20条相似文献,搜索用时 15 毫秒
1.
Gang Li Jeremy J. Harrison Ram S. Ram Colin M. Western Peter F. Bernath 《Journal of Quantitative Spectroscopy & Radiative Transfer》2012,113(1):67-74
Einstein A coefficients and absolute line intensities have been calculated for the E2Π–X2Σ+ transition of CaH. Using wavefunctions derived from the Rydberg–Klein–Rees (RKR) method and electronic transition dipole moment functions obtained from high-level ab initio calculations, rotationless transition dipole moment matrix elements have been calculated for all 10 bands involving v′=0,1 of the E2Π state and v″=0,1,2,3,4 of the X2Σ state. The rotational line strength factors (Hönl–London factors) are derived for the intermediate coupling case between Hund's case (a) and (b) for the E2Π–X2Σ+ transition. The computed transition dipole moments and the spectroscopic constants from a recent study [Ram et al., Journal of Molecular Spectroscopy 2011;266:86–91] have been combined to generate line lists containing Einstein A coefficients and absolute line intensities for 10 bands of the E2Π–X2Σ+ transition of CaH for J-values up to 50.5. The absolute line intensities have been used to determine a rotational temperature of 778±3 °C for the CaH sample in the recent study. 相似文献
2.
《Journal of Molecular Spectroscopy》1986,119(1):166-180
The spin-rotation and hyperfine interactions in the X2Σ+ and B2Σ+ electronic states of 139La16O have been studied using Doppler-free laser-induced fluorescence and molecular-beam laser-rf double resonance. Observations were made for several values of v and many values of N, allowing evaluation of the principal interaction strengths and their N and v dependences for both the X and B states. The results are compared with earlier results for the isoelectronic system 137Ba19F. 相似文献
3.
The emission spectra of CaH and CaD have been recorded at high resolution using a Fourier transform spectrometer and bands belonging to the E2Π-X2Σ+ transition have been measured in the 20 100-20 700 cm−1 region. A rotational analysis of 0-0 and 1-1 bands of both the isotopologues has been carried out. The present measurements have been combined with the previously available pure rotation and vibration-rotation data to provide improved spectroscopic constants for the E2Π state. The constants ΔG(½) = 1199.8867(34) cm−1, Be = 4.345032(49) cm−1, αe = 0.122115(92) cm−1, re = 1.986633(11) Å for CaH, and ΔG(½)=868.7438(46) cm−1, Be = 2.212496(51) cm−1, αe = 0.036509(97) cm−1, re = 1.993396(23) Å for CaD have been determined. 相似文献
4.
The extensive band system belonging to the C2Πr–X2Σ+ transition of boron monoxide (BO) molecule lying in the vacuum ultraviolet region (150–230 nm) has been recorded in emission in a hollow cathode glow. A few new bands involving high v′ levels of C state have been observed. The Franck–Condon factors and r‐centroids were computed for the C–X system. By correlating the measured intensities to theory, the (relative) variation of the C–X electronic transition moment with internuclear separation was examined. 相似文献
5.
6.
The emission spectra of the A2П-X2Σ+ (red) system of 12C14N have been reinvestigated in the 3500-22 000 cm−1 region at high resolution using a Fourier transform spectrometer. In total, spectra of 63 bands involving vibrational levels up to v′ = 22 of the A2П state and v″ = 12 of the X2Σ+ ground state have been measured and rotationally analyzed providing an improved set of spectroscopic constants. The present measurements of the Δv = −2 sequence bands of 12C14N and those of 13C14N from Ram et al. (2010) [36] allow for a much improved identification of these two isotopologues in the near infrared spectra of carbon stars. 相似文献
7.
《Journal of Molecular Spectroscopy》1996,175(1):31-36
TheA1Π–X1Σ+transition of aluminum monobromide (AlBr) near 2800 Å was recorded using a Bruker IFS 120 HR Fourier transform spectrometer at nominal resolutions of 4 and 0.03 cm−1. All bands showP,Q, andRbranches and all are degraded to longer wavelengths. The 0–0 band is the most intense and the Δv= 0 sequence dominates the observed spectrum. Each band appears doubled due to the natural isotopic abundances of79Br (50.69%) and81Br (49.31%). Band origin shifts due to isotopic substitution of bromine were examined to confirm the assignments of isotopic species. The rotational structure of the 0–1, 1–2, 0–0, 1–1, and 2–2 bands was assigned and fitted. These data were merged with previously reported photographic data for the 1–0, 2–1, 3–2, 2–0, and 3–1 bands and also infrared and microwave measurements to provide an improved set of constants for both electronic states. The rotational constants for each vibrational level in theX1Σ+state vary smoothly with increasing vibrational quantum number and thus an expansion of the constants in terms of equilibrium values is recommended. An expansion of theA1Π rotational constants in terms of equilibrium values is not recommended as the distortion constants do not change smoothly with increasing vibrational quantum number. Therefore, the rotational constants for theA1Π state were determined for each individual vibrational level. This approach leads to vastly improved vibrational constants for theA1Π state by reducing correlations between rotational and vibrational constants. This problem is serious for theA1Π state owing to severe departures from harmonic behavior in thev= 2 andv= 3 levels. 相似文献
8.
《Journal of Molecular Spectroscopy》1987,125(1):54-65
The First Negative bands of 12C16O+ and 13C16O+, in the spectral region 40 000–46 000 cm−1, have been photographed at a resolution sufficient to resolve the spin-doubled components. These data for 12C16O+, along with previously reported data of the same transitions, as well as microwave transitions of 12C16O+ in the ground state, have been explicitly included in a least-squares fit to determine the most precise set of molecular constants to date for the B2Σ+ and X2Σ+ states of 12C16O+. Furthermore, we report a rotational analysis of the First Negative bands of 13C16O+ for the first time. Several molecular constants characterizing 13C16O+ in the B2Σ+ and the X2Σ+ states, including spin-doubling parameters, have been determined. 相似文献
9.
Peter J. Domaille Timothy C. Steimle Ning Bew Wong David O. Harris 《Journal of Molecular Spectroscopy》1977,65(3):354-365
Single-mode cw dye laser excitation spectra of the (0, 0), (1, 1), and (2, 2) bands of the B2Σ+-X2Σ+ system of CaCl have been observed and assigned. Some 300 independent photo-luminescence spectra have been used in making the rotational assignment and demonstrate the power of the technique of line-by-line analysis in unraveling complex spectra. Spectroscopic constants (cm?1) obtained from a weighted least squares fit of the data are given below. Numbers in parentheses refer to 95% confidence limits in the last digit.
0 | 16856.69(2) | |
369.8(10) | 366.8(10) | |
1.13(20) | 1.28(20) | |
0.15200(54) | 0.15448(54) | |
0.00063(34) | 0.00073(35) | |
1.027(16) × 10?7 | 1.097(17) × 10?7 | |
(spin-rotation) | +0.003 | ?0.0630(16) |