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1.
New uv absorption spectra have been observed for SiBr. Five Rydberg states are identified to the states , , , , and by comparison with SiF and SiCl. The ionization potentials of SiCl and SiBr have been determined for the first time, and were 6.82 and 6.67 eV, respectively. 相似文献
2.
The electronic absorption spectra of carbon dioxide and carbon disulfide have been reexamined. Model potential calculations have been used to calculate the energies of excited states in Rydberg approximation, and (npσ) and (npπ) Rydberg series have been assigned. For both molecules, the lowest excited 1Πg and 1Πu states are identified as Rydberg states. The lowest state is mainly Rydberg for CO2, but contains some valence character for CS2, There is no evidence for transitions to additional valence states of these symmetries.It is shown that predictions about excited states can be misleading because of near-linear dependencies which arise in multicenter expansions. A consideration of the united atom orbitals for CO2 and CS2 predicts that there should be only the number of low-energy excited states which are found from the spectral analysis. 相似文献
3.
4.
The high resolution absorption spectrum of CO has been reinvestigated in the Hopfield helium continuum region, particularly from 960 to 1080 Å. The Rydberg state 3pπE1Π was extended to v = 2, and other Rydberg states, and F1Σ+, , and and 1Σ+, which are converging to the X2Σ+ ground state of CO+, have been identified. The rotational structures of only five bands among the observed ten Rydberg bands have been analyzed. 相似文献
5.
Shingkuo Shih Sigrid D Peyerimhoff Robert J Buenker 《Journal of Molecular Spectroscopy》1977,64(2):167-179
The vertical transition energies and oscillator strengths from the ground and excited states of the ethynyl radical C2H to all higher-lying states resulting from excitation out of π and σ into and valence-shell MO's, respectively, as well as into 3s and 3p Rydberg species, are calculated by large-scale CI techniques. It is found that the first excited states all result from excitations (the lowest three with quartet character), and not from the 4σ → 5σ counterparts favored in the case of isoelectronic CN. This distinction can be explained on the basis of orbital stability differences caused by the effects of hydrogen mixing. The first six states of the C2H+ ion are also treated, and the correspondence with the various associated Rydberg series is discussed. Dipole moments for the and states are also calculated. 相似文献
6.
We present the first experimental investigation of the photoionization in Pd I using the synchroton radiation facility of the 800 MeV electron storage ring in Berlin (BESSY) and atomic beam technique. The experiments have been concentrated on the study of the Rydberg series of autoionizing levels and nf which lie between the two 4d thresholds. 相似文献
7.
The absorption spectrum of the P18O molecule has been studied in the region 1650–1800 Å. The upper levels of the transitions are shown to be levels of new 2Π valence, 2Π Rydberg and 2Δ Rydberg states of the PO molecule. Most of the levels are perturbed; some of them are predissociated. The new valence state P2Π corresponds to a regular state of the electronic configuration and the 2Π and 2Δ Rydberg states belong to the 5p, 3d, 4d complex series. Perturbations of the P2Π state are shown to arise from Rydberg ~ Non Rydberg interactions with states of same or different symmetry. The complexity of the interactions does not allow to carry out a deperturbation but a comparison with the data of the P16O molecule allows to give a vibrational assignment to the levels of the P2Π state. 相似文献
8.
S.S. Hasnain P. Brint T.D.S. Hamilton I.H. Munro 《Journal of Molecular Spectroscopy》1978,72(3):349-358
The absorption spectrum of naphthalene has been studied in rare-gas matrices (RGM). Molar extinction coefficients have been determined and oscillator strengths of various transitions deduced. Bands in the 6.5 to 7.1 eV region, some of which were previously observed and interpreted as members of an impurity exciton (Rydberg) series, have been assigned to a transition. The results are compared with the theoretical prediction. 相似文献
9.
Accurate SCF computations are reported on the Rydberg states of N2 of electron configurations , , and ---3σg2πg, also on the valence states of the configuration . The Rydberg state calculations supplement those of Lefebvre-Brion and Moser. A comparison is made between the states and the parallel set of states of the configuration. This comparison shows a sharp difference in the 1Σ+ states of the two configurations, the 1Σ+ state being very high in the latter but relatively low in the former configuration. Recknagel coefficients are given for the several states of the two configurations; as expected, these are much smaller for the configuration. Also, the 1Δ state is relatively lower for the latter configuration. 相似文献
10.
Compound nucleus states in and have been investigated with the and three-particle reactions. The observed states (EX≈20 MeV) can be understood, in analogy to the ground states of the A=5 system, by coupling a nucleon to the first 0+ excited state of . 相似文献
11.
The electronic absorption spectrum of cyanogen chloride has been investigated in the range 2200-1250 Å. The first s-Rydberg transitions, and have been assigned, and analyzed to yield exchange and spin-orbit coupling parameters. The relative intensities of these two transitions have been shown to accord with an intermediate coupling situation. The intravalence excitations, leading to 1.3(Σ?, Δ and Σ+) states, have been discussed. It has been shown that one or both of the 1Σ? and 1Δ states have bent geometries and that the 1Σ+ state is located (tentatively) at 79 755 cm?1. Two states have been assigned, one at 56 340 cm?1, the other at 74 450 cm?1. The latter assignment is tentative, being largely based on observed vibronic interferences between the transition and the 74 450 cm?1 transition. A considerable amount of vibrational oscillator strength and quantum defect data is presented. 相似文献
12.
J.D. Petke Gerald M. Maggiora Lester L. Shipman Ralph E. Christoffersen 《Journal of Molecular Spectroscopy》1978,73(2):311-331
Ab initio configuration interaction wavefunctions and energies are reported for the ground state and many low-lying singlet and triplet states of magnesium chlorin and chlorin, and are employed in an analysis of the electronic absorption spectra of these systems.In chlorin, the calculated visible spectrum consists of two states, the lower energy, y-polarized state exhibiting moderate absorption intensity in contrast to the very weak absorption of the higher energy x-polarized state. The configurational composition of both states is well described by the four-orbital model. Five states are responsible for the Soret band envelope. A moderately intense y-state lies under the low energy edge of the band envelope, while two x-polarized states of moderate and strong intensity, respectively, are responsible for the band maximum. The final two states lie at the high energy edge of the Soret band and introduce a measure of asymmetry into the band envelope. Two states of very weak oscillator strength are also found in this region of the spectrum. All the Soret states are of complex configurational composition, and several of the higher lying states contain contributions from doubly excited configurations.The calculated visible spectrum of magnesium chlorin also consists of two states, with the weakly absorbing x-polarized state lying approximately 200 cm?1 lower in energy than the moderately intense y-polarized state. The configurational composition of both states is well described by the four-orbital model. Four states constitute the bulk of the intensity in the Soret band envelope. In distinction to chlorin, the moderately intense state at the low energy edge of the band envelope is x-polarized. Two intense states of y- and x-polarization, respectively, constitute the band maximum region, and a single x-polarized state of moderately strong intensity can be assigned to the high energy shoulder of the band envelope. Two other weakly absorbing states are also found in this region, along with another weakly absorbing state of mixed in-plane and out-of-plane polarization. No clearly defined states are observed. As was the case for chlorin, all the Soret states are of complex configurational composition, and some of the higher energy states contain significant contributions from doubly excited configurations.Chlorin and magnesium chlorin both possess three states which lie below S1 and a single which lies slightly above S2. All four of the low-lying states in each molecule are well described by the four-orbital model, with T1 being essentially a single configuration in each case. The remainder of the states are clustered in the same energetic region as the comparable Soret states, with comparably complex configurational compositions.Dipole moments and charge distributions for low-lying singlet and triplet states are also reported, and are used to rationalize chemical reactivity characteristics. 相似文献
13.
Analog (fp)3 states preferentially excited in the and the reactions have been identified in the mass 43 mirror nuclei. A simple zero-range DWBA calculation made with a cluster form factor gives good agreement with the measured angular distributions, but spectroscopic strengths deduced for mirror levels do not agree. The 3p-0h states are excited with a rather uniform cross section not strongly correlated with spins. 相似文献
14.
R.M. Lieder A. Neskakis M. Müller-Veggian Y. Gono C. Mayer-Böricke S. Beshai K. Fransson C.G. Linden Th. Lindblad 《Nuclear Physics A》1978,299(2):255-284
High-spin states in 195, 197Tl have been populated with (α, xn) reactions and studied by means of in-beam γ-ray and e? spectroscopic methods. Complementary studies of the decay of 195, 197Pb to 195, 197Tl have been carried out. Several new features have been observed in these nuclei. The bands of 195, 197T1. extended to and , respectively, show a quenching of energy spacings between the , , and states. This has been interpreted as resulting from the coupling of a proton to the ( configurations in the core nuclei 194, 196Hg. Furthermore, positive-parity bands based on states were established up to the and states in 195, 197Tl respectively. Probably these bands originate from the coupling of a h proton to a broken neutron pair. This pair consists of a rotation-aligned neutron and a low-j neutron in the , or shell. It is known to constitute the 5? bands in 194, 196Hg. 相似文献
15.
Robert S. Mulliken 《Journal of Molecular Spectroscopy》1976,61(1):92-99
Predissociations in the y1Πg and Rydberg states of N2 (configurations and , respectively) and their likely causes, are discussed. Peaking of rotational intensity at unusually low J values, without sharp breaking off, is interpreted as due to case c? or case ci predissociation. Λ doubling in the y state, attributed to interactions with the state and with another, 1Σ+, state of the same electron configuration as x, is analyzed. From this analysis the location of the (unobserved) state, here labeled x′, is obtained. It is concluded that the predissociation in the Π+ levels of the y state is an indirect one mediated by the interaction with x′ coupled with predissociation of x′ by a state dissociating to atoms: combined, however, with perturbation of the y state by the k1Πg Rydberg state (configuration ), whose Π+ levels are completely predissociated. 相似文献
16.
U. Becker H. Kerkhoff M. Kwiatkowski M. Schmidt U. Teppner P. Zimmermann 《Physics letters. A》1980,76(2):125-127
A beam of metastable silicon atoms was produced by collisional dissociation of silicon molecules and selectively excited by a pulsed dye laser. The lifetimes of the excited Si I states were directly determined from the fluorescence decay curve: , , . 相似文献
17.
Analyzing powers have been measured for six states from the reaction and seven states from the reaction. These studies were performed with a beam from a new polarized triton source, and the reaction protons were detected in a Q3D spectrometer. The analyzing powers and differential cross sections are adequately described by DWBA calculations for both the medium and heavy targets up through L-transfers of 4. Above this value, some disagreement is seen. 相似文献
18.
We have studied vacuum ultraviolet luminescence spectra of nitrogen crystals at different excitation densities. Forbidden transitions from three singlet states , have been observed. A non-linear dependence of luminecence of the excitation intensity has been found. A characteristic feature of the singlet transitions observed is a fine structure of vibronic bands. The luminescence spectra of pure crystalline nitrogen is compared with those of impurity luminescence of solid solutions N2—Ar. The nature of singlet luminescence of nitrogen crystals is discussed proceeding from the two-particle radiation mechanism. 相似文献
19.
Dicke superradiance in the 1.30-μm transition in Tl vapor has been induced by a 379.1-nm pulsed dye laser. Superradiant delays of up to 12 nsec have been observed. 相似文献
20.
The alpha-decay of states in 18O have been studied in the inelastic scattering reaction at 82 MeV. The double differential cross sections have been analysed with a strong absorption model. A systematic dependence of emission angle on spin is observed, allowing the determination of the transferred angular momentum. 相似文献